Sentence Combining Practice: 20 Exercises With Answers

Read these two sentences out loud: “I was hungry. I made a sandwich.” Both are correct, but together they sound like a robot wrote them. Now read this: “I was hungry, so I made a sandwich.” Same facts, same words, and it sounds like a person.

That small jump is what sentence combining teaches. You take short, choppy sentences and join them so the reader can feel how the ideas connect. It’s a skill that improves your essays, your emails, your exam answers and your speaking, and the only way to build it is practice.

This page gives you 20 sentence combining exercises in five groups, with a full answer key and a short reason for every answer. You’ll also get a three-word routine, a connector cheat sheet and a self-check list. I’ve taught English grammar for 22 years, and the students who improve fastest are the ones who try the exercise before reading the answer. If you want the method behind these exercises first, read my guide on how to combine two sentences into one.

Why practise sentence combining

Most learners write in short sentences because short sentences feel safe. There’s nothing wrong with that, but a page full of them reads like a list. Combining gives you three things at once.

Every sentence in this practice set is original and written for learners at an intermediate level. Several pairs have more than one correct answer, so if yours differs from mine, check it with the self-check list near the end.

Connector cheat sheet

The Ask, Pick, Join routine

Don’t grab and every time. If you can’t name the relationship, you’re not ready to choose the connector. Name it first, and the connector almost chooses itself.

Group A: and, but, so, or

These connectors join two equal sentences. Use a comma before but, so and or when each side is a full sentence. If both parts share the same subject, you can often drop the second subject and the comma. A classic memory trick is FANBOYS: for, and, nor, but, or, yet, so. For more on commas, see comma rules in English grammar.

1. I was hungry. I made a sandwich.
2. She likes tea. She doesn’t like coffee.
3. You can take the bus. You can walk.
4. He opened the window. He turned on the fan.

Group B: because, although, since

These make one idea depend on the other. Because answers the question why. Although and though say despite this. When the connecting clause comes first, put a comma after it. When it comes second, you usually don’t need one. Memory trick: “Because gives a reason. Although gives a surprise.”

1. We stayed home. It was raining.
2. She was nervous. She spoke clearly.
3. The shop was closed. We went to the market.
4. He is young. He is very wise.

Group C: time and condition

Time words (when, after, before, as soon as) and condition words (if, unless) also make one clause depend on another. Remember that the future doesn’t take will in these clauses: say “when I reach home,” not “when I will reach home.” For harder if-patterns, see third and mixed conditionals. Memory trick: “If-clause first, comma next.”

1. Finish your homework. Then you can play.
2. Leave now. You will miss the train.
3. I will call you. I reach home.
4. The bell rang. The students ran out.

Group D: who, which, that, whose

These connectors turn the second sentence into a description of a noun in the first. Use who for people, which for things, that for either when the information is essential, and whose for ownership. If the extra detail isn’t essential, put commas around it. For the full rules, read relative clauses: who, which and that. Memory trick: “Who for people, which for things.”

1. I know a teacher. She teaches music.
2. This is my laptop. It was a gift.
3. The book is on the table. It belongs to Rahul.
4. My neighbour is a doctor. His clinic is nearby.

Group E: -ing, -ed and to phrases

When both sentences share the same subject, you can turn one into a short phrase. Use an -ing phrase for something happening at the same time or just before, having plus a past participle for something finished first, and to plus a verb for purpose. Read more about these in types of phrases. One warning: the doer of the phrase must be the subject of the main sentence. Memory trick: “Same doer, or don’t use it.”

1. She finished her work. She went home.
2. He was tired. He fell asleep quickly.
3. She wanted to relax. She switched off her phone.
4. The thief was caught. He was running away.

Answer key with reasons

Cover this section until you’ve tried all 20. Your wording can differ from mine, as long as the relationship and the punctuation are right.

How to check your own answer

If you got 17 or more right, you’re ready for harder material such as the difference between a clause and a phrase, which is explained in phrase vs clause. If you scored below 12, re-read the group introductions and retry only the groups you missed.

Mistakes to avoid

A pattern I see in almost every batch

Learners can usually recite the connector lists. Where they struggle is the choice. Give them “It was raining. We played football,” and half will write “It was raining and we played football.” It’s grammatical, but it hides the surprise. The fix is simply to say the relationship aloud first: “That’s a contrast.” Then although appears on its own.

Expert tips for practice

Frequently asked questions

What is sentence combining?

It’s joining two or more short sentences into one longer sentence so that the relationship between the ideas is clear. You can use connectors, relative pronouns or short phrases.

Should I always use a comma when I combine sentences?

Not always. Use a comma after an opening clause and before but, so or or when each side is a full sentence. You usually don’t need one when the connecting clause comes second, as in “We stayed home because it was raining.”

Can there be more than one correct answer?

Yes. Many pairs can be joined in several correct ways. What matters is that the connector matches the relationship, no detail is lost and the punctuation is right.

How many sentences should I combine at once?

Two is a good start. Joining three or more often makes a sentence that’s hard to read, even when each connector is correct.

Is sentence combining useful for exams?

Yes. Sentence improvement and sentence transformation questions test the same skill. Always check the latest official notification for your exam pattern.

Your next step

Pick one group and try the four exercises today, before you look at the answers. Ask how the ideas relate, pick the connector, then join and check. That’s the whole routine.

When you want a fast, repeatable way to handle clauses and phrases, my ebook Clauses & Phrases Demystified: Fix Errors and Write Confidently is on Amazon: https://amzn.to/4ibEcP9

Which group felt hardest? Tell me in the comments, and I’ll explain it in more detail.

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