Boundaries

Introduction

These questions require you to understand whether a sentence is complete or not, and to decide how to fill in the blank based on your assessment.

There are 3 types of boundaries questions:

1. Verb activation questions (as opposed to conjugation and verb agreement questions) will include only one answer choice with an active verb (runs), and three answer choices with inactive verbs (to run, running, having run).
2. Punctuation questions require you to choose between a semicolon, colon, dash, and comma.
3. Connectors and demotion questions will include at least one answer choice with which, that, or who, and at least one answer choice without which, that or who.

We'll look at all three of these types, how to identify which type you're dealing with, what rules you need to know, and what the common traps are in each category.

But first, we need to talk about your ear.

Complete or Incomplete?

In technical terms, a full sentence must contain at least one independent clause, but I generally wouldn't advise that you use spend a lot of time searching for subjects and verbs to assess whether a sentence is complete or not. In my experience the best approach is to simply trust your ear.

Here are some examples

Clause	Complete?
it is blue	yes
it was blue	yes
it will be blue	yes
it has been blue.	yes
It will have been blue	yes
it had been blue	yes
It being blue.	yes
it having been blue.	yes
It to be blue.	yes
You walk.	yes
You walked.	yes
You will walk.	yes
You have been walking.	yes
You will have been walking.	yes
You had been walking.	yes
You walking.	yes
You having walked.	yes
You to walk	yes
The woman running for President is rich.	yes
The woman running for President was rich.	yes
The woman running for President will be rich.	yes
The woman running for President has been rich.	yes
The woman running for President will have been rich.	yes
The woman running for President had been rich.	yes
The woman running for President.	no
The woman to run for President.	no
The woman running for president being rich.	no
The woman running for president to be rich.	no
I like cats.	yes
Because I like cats.	no
I adopted a cat because I like cats.	yes
Because I like cats, I own several.	yes
The car which is blue.	no
The car is blue.	yes
The car, which is blue, is very fast.	yes
This is good.	yes
I was running for the bus.	yes
I like running.	no
Running for the bus	yes
Running for the bus makes you sweat.	yes
Running for the bus	yes
Running for the bus, Bob got tired.	yes

If you find you’re having difficulty telling the difference, I recommend you try reading outloud more often, listening for the main verb or verbs in a sentence. You can also consult a more traditional grammar resource, but I would not recommend that you get lost in grammar rules. If you are generally getting these questions right, you shouldn’t waste time learning the details of grammar — you’ll find it’s way too much information for the SAT and almost certainly not helpful.

Type 1: Activating the Verb

Complete sentences in English must have at least one active verb. The SAT tests this concept with questions in this structure:

Running for the bus, Bob ___________ on a banana peal.

1. slipping
2. to slip
3. slipped
4. having slipped

Solution

The correct answer here is (C) because it is the only option that forms a complete sentence:

Running for the bus, Bob slipped on a banana peal.

The verb to slip is only active if it is conjugated, which generally means it must have a subject. In the case above, Bob is the subject, i.e. Bob performed the action (Bob slipped.)

Identification

Verb activation questions (as opposed to conjugation and verb agreement questions) will include only one answer choice with an active verb (runs, for example), and three answer choices with inactive verbs (to run, running, having run, for example).

Say you are given these four answer choices:

1. smoke
2. to smoke
3. smoking
4. being smoked

Only one option contains an active (conjugated) verb ⇒ answer choice (A). This means that the question is asking you to identify whether or not we want to have an active verb here. And most of the time, the active verb option will be the correct one — although you should always actually read the sentence carefully.

Listening for the active verb

These questions are typically on the easier end of the spectrum, and you should trust your ear to tell you what is or isn’t a complete sentence.

Exercises

Question 1

Some people buy organic food because they believe organically grown crops are more nutritious and safer for consumption than their conventionally grown counterparts, which are usually produced with pesticides and synthetic fertilizers. In the name of health, _______ $1.60 for every dollar they would have spent on food that is conventionally grown.

1. spending
2. these consumers spend
3. having spent
4. to spend

Solution

The correct answer is (B) because it’s the only option with a subject (these consumers) and an active verb (spend).

Question 2

Explaining his company’s decision to expand its tuition-assistance program, John Fox, the director of dealer training at Fiat Chrysler Automobiles in the United States, ____________ the importance of drawing skilled employees to Fiat Chrysler’s car dealerships: “This is a benefit that can surely bring top talent to our dealers,” he said.

1. who stressed
2. stressed
3. stressing
4. and he stressed

Solution

The correct answer is (B) because it’s the only option with an active verb (stressed).

Type 2: Punctuation

Identification

Identifying these questions is pretty easy. In short, Boundaries>Punctuation questions require you to choose between:

1. semicolon
2. colon
3. dash
4. comma

If you have to choose between any 2 out of 4 of these punctuation marks, then you are dealing with a Boundaries>Punctuation question, and you are in the right place.

The rules for joining clauses with punctuation are generally not taught in school, so even proficient English speakers struggle with these questions at first. The good news is that the rules are simple enough to learn and generally easy to apply. Here’s a simplified example of boundaries question with punctuation:

Hoping to get a good ______ I studied every day.

1. grade,
2. grade;
3. grade—
4. grade:

Solution

The correct answer here is (A) because semi-colons, dashes, and colons must all have a full sentence on their left hand side. Hoping to get a good grade is not a full sentence, so (B), (C), and (D) must all be incorrect, which leaves us with answer choice (A).

Ok, fine, but why? Let’s look at each punctuation mark more closely.

Semicolons and periods

tip

In terms of English syntax, semicolons and periods are always interchangeable. And since we cannot ever have two correct answers on the SAT, if you see two answer choices that are identical except one uses a period and the other uses a semicolon, they must both be incorrect.

In other words, both periods and semicolons are used to seperated complete sentences from one another. These sentences, therefore,

✅ I like cats. You like dogs.

✅ I like cats; you like dogs.

are both correct because there is a full sentence on both the right and left hand side of the punctuation mark.

These sentences, meanwhile,

❌ I spent last summer in Paris. A beautiful city.

❌ I spent last summer in Paris; a beautiful city.

are both incorrect because the right hand side of the punctuation mark contains a fragment.

Similarly,

❌ Running for the bus. I slipped.

❌ Running for the bus; I slipped.

are both incorrect because the left hand side is a fragment.

If you are given these answer choices, therefore

Given these four answer choices, what can you conclude?

1. pickles;
2. pickles.
3. pickles,
4. pickles—

You can safely delete answer choices (A) and (B). They cannot both be right so they must both be wrong!

Important Exception

Semicolons can also be used to delimit items in long, complicated lists where each item contains one or more commas. For example, if we have a short list like this:

I like Mexican food, French food, and Italian food.

The list and its items are clearly visible.

But if we add a bunch of details to the list, it can get unruly pretty quickly:

I like Mexican food for its bold flavors, spice, and acidity, French food for its refined dishes and history, and Italian food for its high quality ingredients, tradition, and cheese.

To make this clearer, let’s add semicolons between items:

I like Mexican food for its bold flavors, spice, and acidity; French food for its refined dishes and history; and Italian food for its high quality ingredients, tradition, and cheese.

Colons

Colons must have an independent clause on their LHS. On their RHS they can have either a fragment or a full sentence. All of these sentences, therefore

✅ I quit for a good reason: my boss was evil.

✅ I love all kinds of movies: horrors, comedies, and romances.

✅ The key to health and happiness can be summed up in one word: fondue.

are correct because the LHS of each colon could form a stand-alone sentence.

These examples, meanwhile,

❌ Poker: it’s a wonderful game.

❌ Last night at the disco: we danced all night.

❌ Earlier I went shopping for: bread, bananas, and yogurt.

❌ I love films such as: horrors, comedies, and romances

are all incorrect because the LHS of each colon does not form a complete sentence. But wait — aren’t colons good for introducing lists?

danger

⛔ Yes, colons are good at introducing lists, but DON’T FALL FOR THIS COMMON TRAP: colons must still have a full sentence on their LHS even they are introducing a list. If the LHS isn’t a complete sentence, the colon is simply wrong.

To fix these:

❌ Earlier I went shopping for: bread, bananas, and yogurt.

❌ I love films such as: horrors, comedies, and romances

We can make the LHS into a full sentence:

✅ Earlier I went shopping for these items: bread, bananas, and yogurt.

✅ I love films such as these: horrors, comedies, and romances

Dashes

Dashes are pretty similar to colons in some ways, but the two differ in some important ways as well. For now let’s keep it simple and say that a dashe, like a colon, must have an independent clause on its LHS. On its RHS it can have either a fragment or a full sentence. All of these sentences, therefore

✅ I love all kinds of movies—horrors, comedies, and romances.

✅ I quit for a good reason—my boss was evil.

✅ The key to health and happiness can be summed up in one word—fondue.

are correct because the LHS of each dash could form a stand-alone sentence.

These examples, meanwhile,

❌ Poker—It’s a wonderful game.

❌ Last night at the disco—we danced all night.

❌ Earlier I went shopping for—bread, bananas, and yogurt.

❌ I love films such as—horrors, comedies, and romances

are all incorrect because the LHS of each colon does not form a complete sentence.

Dashes vs colons

info

ℹ️ Colons and dashes each require a full sentence on the left hand side, but they are NOT totally interchangeable. The colon, generally speaking, is less versatile than the dash. In other words if you’re stuck between the two, the dash is probably the better guess.

1. Dashes are more versatile than colons

   Occasionally on harder questions you’ll be faced with a choice between a colon and dash, where both options have a full sentence on the LHS of the punctuation. In other words, the rules mentioned above are not sufficient to solve the problem. Here is an example:

   I was bored at the wedding: so I went home.

   I was bored at the wedding—so I went home.

   Both options have a complete sentence on their LHS, so what’s the right answer here? The key here is that colons are very rarely followed by conjunctions (words like so, and, but, because) whereas this isn’t a problem with dashes.

In fact, there are few standard forms that just don't fit with a colon:

ing forms are no good after a colon

I studied all night: hoping to get a good grade.

conjuctions are no good either

I studied all night: because I wanted to get a good grade. I was bored at the wedding: so I went home.

relative pronouns don't work:

• I bought an expensive car: which broke down after a day.*

In fact, there are few standard forms that just don't fit with a colon:

ing forms are no good after a colon I studied all night— hoping to get a good grade.

conjuctions are no good either I studied all night—because I wanted to get a good grade. I was bored at the wedding—so I went home.

relative pronouns don't work

• I bought an expensive car—which broke down after a day.*

2. Dashes can come in pairs

   Dashes, unlike colons, can sometimes come in pairs. In other words, you might find a sentence with two dashes in it, like this one:

   ✅ Bob (my best friend) is French. ✅ Bob—my best friend—is French. ✅ Bob, my best friend, is French.

   This sentence is correct because the dashes are being used as brackets, so rule about how a dash must have a complete sentence on its left no longer applies.

Commas

Commas are tricky in English. In this short section we’ll be looking ONLY at the rules governing comma usage between clauses.

Is this correct?

? I like cats, they are fluffy.

No. This is what's known as a run-on or comma splice.

The basic rule is that a comma cannot join two complete sentences. These sentences, therefore,

info

ℹ️ When two full sentences are incorrectly joined with a comma, we call this a comma splice or run-on sentences.

❌ I like cats, they are fluffy.

❌ Geoff got home at 4am, he woke up exhausted.

❌ Spain is a beautiful country, its beaches are the best in the world.

are all incorrect because in each the comma has a full sentence on its right and its left hand sides.

We can easily fix these run-on sentences in a few different ways.

1. We can add a conjunction

   ❌ I like cats, they are fluffy.

   ✅ I like cats because they are fluffy.

2. We can change the comma into a different punctuation mark

   ❌ Geoff got home at 4am, he woke up exhausted.

   ✅ Geoff got home at 4am; he woke up exhausted.

   ✅ Geoff got home at 4am—he woke up exhausted.

   ✅ Geoff got home at 4am: he woke up exhausted.

3. We can convert either the left or right hand side into a fragment

   ❌ Spain is beautiful country, its beaches are the best in the world.

   ✅ Spain is a beautiful country, its beaches the best in the world.

   ✅ A beautiful country, Spain has the best beaches in the world.

   ✅ Spain is a beautiful country, which has the best beaches in the world.

Overview of rules

Joining two full sentences

Full Sentence	connection	Full Sentence	Correct?
I like cats	.	They are fluffy.	works
I like cats	; (semi-colon)	they are fluffy.	works
I like cats	— (dash)	they are fluffy.	works
I like cats	: (colon)	they are fluffy.	works
I like cats	because (conjunction)	they are fluffy.	works
I like cats	, (comma)	they are fluffy.	incorrect — this is known as a comma splice or run-on sentence

Joining a full sentence to a fragment

Full Sentence	connection	Fragment	Correct?
This is Bob	.	My best friend.	incorrect
This is Bob	; (semi-colon)	my best friend.	incorrect
This is Bob	— (dash)	my best friend.	works
This is Bob	: (colon)	my best friend.	works
I studied for a week straight	, and (conjunction)	hoping to get a good grade.	incorrect
This is Bob	, (comma)	my best friend.	works

Joining a fragment to a full sentence

Fragment	connection	Fragment or Full Sentence	Correct?
Running for the bus	.	I slipped.	incorrect
Running for the bus	; (semi-colon)	I slipped.	incorrect
Running for the bus	— (dash)	I slipped.	incorrect
Running for the bus	: (colon)	I slipped.	incorrect
Running for the bus	and (conjunction)	I slipped.	incorrect
Running for the bus	, (comma)	I slipped.	correct.

Exercises

Question 1

For as long as Harvey Houses served rail travelers through the mid-twentieth century, working there was a steady and lucrative position for women. Living independently and demonstrating an intense work _______ the Harvey Girls became known as a transformative force in the American West.

1. ethic;
2. ethic:
3. ethic, and
4. ethic,

Solution

(D)

Question 2

Based on scientific evidence, organic food offers neither significant nutritional nor safety benefits for consumers. Proponents of organic food, of course, are quick to add that there are numerous other reasons to buy organic ______ a desire to protect the environment from potentially damaging pesticides or a preference for the taste of organically grown foods.

1. food, such as,
2. food such as:
3. food, such as:
4. food, such as

Solution

(d)

Question 3

In the mid-1800s food available on rail lines was generally of terrible quality. To capitalize on the demand for good food, Fred Harvey, an English-born _________ decided to open his own restaurant business to serve rail customers.

1. entrepreneur. He
2. entrepreneur:
3. entrepreneur; he
4. entrepreneur,

Solution

(d)

Question 4

Employees whose tuition is reimbursed by their employer often stay with their employer even after they complete their ________ their new qualifications give them opportunities for advancement within the company.

1. degrees. Because
2. degrees: because
3. degrees because
4. degrees; because

Solution

(C)

Question 5

Marsupials (mammals that carry their young in a pouch) are a curiosity among biologists because they lack a corpus callosum, the collection of nerve fibers connecting the two hemispheres of the brain. In most other mammals, the left hemisphere of the brain controls the right side of the body, the right hemisphere controls the left, and the corpus callosum allows communication between the hemispheres. Scientists have long believing that this structure enables complex tasks by sequestering skilled movement to a single hemisphere without sacrificing coordination between both sides of the body; this sequestration would explain handedness, the tendency to consistently prefer one hand over the other, in humans. However, a recent finding of handedness in marsupials suggests that a __________ other than the presence of a corpus callosum correlates with handedness: bipedalism.

1. trait
2. trait,
3. trait;
4. trait:

Solution

(A)

Question 6

Fieldwork in a city has to be done intermittently: the construction crew had to proceed one block at a time to avoid interrupting traffic, and the archaeology team’s work was periodically _________ by stormy weather and the discovery of toxic materials underground.

1. halted—
2. halted;
3. halted,
4. halted

Solution

(D)

Question 7

The Cat in The Hat, written by Theodor Geisel in 1954, was a hit. In the years that ______ talented writers and illustrators of children’s books imitated Geisel’s formula of restricted vocabulary and whimsical artwork.

1. followed. Many
2. followed; many
3. followed, many
4. followed—many

Solution

(C)

Type 3: Connectors & Demotion

Identification

These questions can be a little harder to spot at first because there is a little more variety in how the answer choices are presented.

You may, for example, have to choose between:

1. and
2. but
3. however
4. [blank]

Or they may throw some relative pronouns into the mix:

1. which
2. that
3. [blank]

Or the answer choices may look pretty much identical to the verb activation question types we looked at earlier:

1. running
2. that ran
3. run
4. having run

Or you might have a mix of punctuation style options with any of the above:

1. hair, but
2. hair, however,
3. hair;
4. hair,

Let's move on to the concepts, then, and you'll start to see how it all ties together soon.

Conjunctions

Conjunctions are words that allow us to connect two sentences syntactically. In other words, they can act as replacements for periods and semi-colons, and even colons and dashes in some cases.

Here is an overview of the main conjunctions.

type	conjunctions	sample sentences	comment
coordinating conjunctions	for and nor but or yet so	I ate, for I was hungry. I like cats, and I like dogs. I don't like cats, nor do I like dogs I like cats, but I don't like dogs. I need to eat now, or I might faint. I like cats, so I bought one. I like cats, yet I don't own one.	not important: nor, for, or important: and, but, so
subordinating conjunctions	because since while as	Because I was hungry, I ate lunch. I have been playing chess since I was six years old. While you were at the store, I was at home. As you already know, I love cats.	subordinating conjunctions can be placed at the start of the sentence or between the sentences.

And here are some typical mistakes, along with their corrections, that you might encounter in an SAT boundaries question.

Run-on sentences

❌ I like cats, they are fluffy.

✅ I like cats because they are fluffy.

Double-conjunctions

❌ Because I like cats, so I bought one.

This sentence has two conjunctions where we only need one. To fix the issue we only need to delete one of the two conjunctions, and we're good.

✅ Because I like cats, I bought one.

✅ I like cats, so I bought one.

Conjunctive Adverbs

Conjunctive adverbs are words we use to connect the ideas between sentences. Here are some examples of conjunctive adverbs:

however, therefore, nevertheless

These words share some properties with conjunctions, namely that both types of words connect ideas:\

I am hungry. However, I won't eat anything.

I am hungry, but I won't eat anything.

In both cases, the words however and but serve to illustrate that there is a contrast between the first and second ideas.

Despite the name, though, conjunctive adverbs are not conjunctions, but adverbs. In other words, theycannot join full sentences on their own.

Adverbs in general are always optional. If you see one of these conjunctive adverbs, you can take it out of the sentence completely and the sentence will be structurally correct if it was structurally correct with the adverb, and it will wrong if it wrong with the adverb.

This means that this sentence is incorrect:

I am hungry, however, I won't eat anything.

Can you think of why the above sentence is wrong? How might you fix them based on the rules we've covered so far?

All four are run-on sentences because the conjunctive adverbs don't connect sentences syntatically.

❌I am hungry, however, I won't eat anything.

✅I am hungry; however, I won't eat anything.

✅I am hungry. However, I won't eat anything.

✅I am hungry—however, I won't eat anything.

These are just a few of the possible ways we could fix this run-on sentence without changing the underlying structure too much.

Adverbs can be placed in many locations in a sentence.

I like cats. However, I don't own one.

I like cats. I, however, don't own one.

I like cats. I don't, however, own one.

I like cats. I don't own one, however.

Adverbs can be placed in many locations in a sentence.

I like cats. However, I don't own one. I don't have time to take care of one.

I like cats. I, however, don't own one. I don't have time to take care of one.

I like cats. I don't, however, own one. I don't have time to take care of one.

I like cats. I don't own one, however. I don't have time to take care of one.

danger

⛔ Conjunctive adverbs are not conjunctions so they can’t join sentences by themselves. They can be used with semicolons, colons, or dashes, however. Here are some examples:

❌ I like cats, however, I don’t own one.

✅ I like cats; however, I don’t own one.

❌ I like dogs, for instance, I love Westies.

✅ I like dogs: for instance, I love Westies.

Demotion

Demotion is when you merge two sentences by converting one of them into a fragment.

For example, these two sentences,

Last summer I visited France. France is a beautiful country.

could really be merged into a single sentence. Can you think?

How can we merge the two sentences above to be more concise?

Last summer I visited France, a beautiful country.

By demoting the second sentence into a fragment, we avoid repetition.

You can demote a sentence in different ways. How might you fix some of these run-ons?

❌ I was running for the bus, I slipped.

❌ I studied all night long, I was hoping to get a good grade.

❌ I bought an expensive car, the car was stolen a day later.

❌ I met a woman, her shoes were bright green.

How can we fix the run-on sentences above by demoting one of the two independent clauses?

Here are some of the ways we can fix the above sentences by demoting either right or left hand side into a fragment.

❌I was running for the bus, I slipped.

✅Running for the bus, I slipped.

❌I studied all night long, I was hoping to get a good grade.

✅I studied all night long, hoping to get a good grade.

❌ I bought an expensive car, The car was stolen a day later.

✅I bought an expensive car which was stolen a day later.

❌I met a woman, Her shoes were bright green.

✅I met a woman whose shoes were bright green.

By demoting the second sentence into a fragment, we avoid repetition.

Exercises

Question 1

1-MCP is a chemical fruit sellers use to keep their fruits looking fresh. This chemical works by limiting a fruit’s production of ethylene, ________ a chemical that causes fruit to ripen and eventually rot.

1. it is
2. being
3. that is
4. LEAVE the space blank

Solution

(D)

Question 2

Many librarians, whose training now includes courses on research and Internet search methods, teach classes in Internet navigation, database and software use, and digital information literacy. While these classes are particularly helpful to young students developing basic research skills, _________ adult patrons can also benefit from librarian assistance in that they can acquire job-relevant computer skills.

1. but
2. and
3. for
4. LEAVE the space blank

Solution

(D)

Question 3

Since public transport systems that go fare-free see increases in ridership, they often must operate more buses and trains and hire more drivers and other personnel at the same time that they are losing a key source of funding. Advocates of fare-free policies claim that the costs of these policies are largely offset by various ___________ a recent study comparing projected results of fare-free policies in different cities found this outlook to be overly optimistic.

1. savings, however,
2. savings,
3. savings, but
4. savings; and

Solution

(C)

Question 4

A video game designer envisions the game’s fundamental elements—the settings, characters, and plots that make each game unique—and is thus a primary creative force behind a video game. Conceptualizing a game is only the beginning of a video game designer’s _________ matter how good a concept is, it will never be translated into a video game unless it is communicated effectively to all the other members of the video game development team.

1. job, however, no
2. job, however. No
3. job—however, no
4. job however no

Solution

(B)

(A) and (D) are run-ons because conjunctive adverbs can't join full sentences. (C)

1. A video envisions the elements, but conceptualizing the game is only the beginning.
2. Conceptualizing the game is only the beginningm, but it will never be turned into a game without communication.

Question 5

1-MCP is a chemical fruit sellers use to keep their fruits looking fresh. But some fruits do not respond as well to 1-MCP as others do, and some even respond adversely. Furthermore, some fruits, particularly those that naturally produce a large amount of ethylene, do not respond as well to 1-MCP treatment. Take Bartlett ________ unless they are treated with exactly the right amount of 1-MCP at exactly the right time, they will remain hard and green until they rot, and consumers who experience this will be unlikely to purchase them again.

1. pears, for instance,
2. pears, for instance:
3. pears for instance,
4. pears. For instance,

Solution

(B)