So I put her(my pet turtle) in the water and blocked the sunlight, but she got worse.

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1. She got worse.
2. She got bad.
3. She got best.
4. She got better.
5. She got well.

(Can we use all the expressions? Are they all grammatical? Instead of #1 can we use #2 in the example sentence?)

Well, I don't think you can use #2, but you could use

#1 and #4.

We also use # 5.

yeah, that too

Do you mean we can use 'she got bad' in the example sentence?

Do you mean we cannot use 'she got bad' in the example sentence?

No. We wouldn't say: "I put her(my pet turtle) in the water and blocked the sunlight, and she got bad"

Say that out loud, and see how silly it sounds. :)

Thank you. you mean"but she got bad" is staange?

What about the following?

"...but she became bad."?

No ... only #s 1, 4, and 5 would be correctly used.

When you say "worse," you say that the turtle's condition became more bad when you put her in the water. If you say bad, it means that she was good at first, but then became bad.