You don't need to repeat the subject after "but" if both parts of your sentence (clauses) have the same subject. Therefore, you can mention it again or omit it in the second clause.

You don't need to repeat the subject after but in English if both parts of your sentence (clauses) have the same subject. You can mention it again or omit it in the second clause.

1. The Right Choice Regarding Subject Repetition

You can choose whether to repeat the subject pronoun after but by considering a range of factors, including emphasis, rhythm, stress, and clarity.

Avoiding word repetition, also known as ellipsis, is quite common and makes you sound more natural in English. Look at these examples:

He bought tickets, but he didn't go to the game.

He bought tickets but didn't go to the game.

Both are correct, but the second sentence sounds more natural. Additionally, getting your ideas across in as fewer words as possible helps you communicate more effectively.

Occasionally, however, subject repetition is included to improve the rhythm or the stress of the sentence. It can also be used for emphasis or clarity when the sentence is long. For example:

I study German on Tuesday nights, but on Friday nights I go out with my friends.

Complicated and long sentences may be difficult to follow when the subject is omitted from the second clause. For example:

Alice reported each new development of the crisis to the board of directors, and how the CEO was aware of the situation but decided to do nothing.

Omitting the subject after but creates some degree of uncertainty because the subject ("who decided to do nothing") could be Alice, the board of directors, the CEO, or someone else.

2. Subject Repetition and Comma Usage

Add a comma before but if the second clause forms a complete sentence; that is, if you repeat the subject after but.

James was hungry, but he had nothing in the fridge.

James was hungry but he had nothing in the fridge.

3. Omitting the verb and the subject

Look at this example:

He said he would come, but he didn't come.

Instead of omitting the pronoun of the second clause, we can omit the verb come.

He said he would come but he didn't.

We also can omit both, the pronoun and the verb:

He said he would come but didn't.

For clarity, we can take out the verb while keeping the subject pronoun:

I hope my computer works, but I don't think it will.

4. More Examples

Let's examine more examples regarding subject repetition with the coordination conjunction but.

Repeating the Subject

• My niece walks to school, but she takes the bus home in the afternoon.
• Your daughter speaks French very well, but she needs to work on her writing skills.
• My aunt plays the piano in the afternoon, but she watches TV in the evening.
• I am dating Rebecca, but I love Alice.
• My mother eats eggs, but she doesn't eat meat.

Without Repeating the Subject

• The watch is waterproof but expensive.
• We need milk but not butter.
• I like oranges but don't like apples.
• He is tall but not handsome.
• They enjoy going to the park but not going to the movies.
• I practice weight lifting on Fridays but not on Saturdays.

5. Conclusion

You can follow these guidelines regarding subject repetition and comma usage with but:

1. Find the coordinating conjunction but in the sentence.
2. Study the clauses on either side.
3. Place a comma before but if the second clause forms a complete sentence; that is, if you repeat the subject after "but" and the clause forms a complete sentence.