1. I try not to stress when things go wrong.

2. I try not to stress out when things go wrong.

3. I try not to stressed when things go wrong.

4. I try not to stressed out when things go wrong.
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Are they all grammatical? What is the difference among them?

3 and 4 are incorrect.

1 is awkward.

2 is correct.

Thank you for your help.

5. Driving in cities really stresses me (out).

Can we delete 'out' without changing the meaning?

Out of the four sentences you provided, only two of them are grammatically correct. Sentence 1 and sentence 2 are both grammatically accurate, while sentence 3 and sentence 4 contain errors.

The difference between the correct sentences lies in the presence of the word "out." Sentence 1 does not include "out," while sentence 2 does.

1. "I try not to stress when things go wrong."

This sentence is grammatically correct. It means that the person is making an effort to avoid feeling stressed when things do not go as planned.

2. "I try not to stress out when things go wrong."

This sentence is also grammatically correct. It has a similar meaning to the first sentence but includes the word "out." The addition of "out" adds emphasis to the stress the person is trying to avoid. It implies that the person is consciously making an effort to prevent themselves from becoming highly stressed in difficult situations.

On the other hand, sentences 3 and 4 have issues with tense agreement:

3. "I try not to stressed when things go wrong."

This sentence is grammatically incorrect. To create the correct verb form, you should use "stress" instead of "stressed" to match the present tense of "try" and "go."

4. "I try not to stressed out when things go wrong."

This sentence is also grammatically incorrect. Similar to sentence 3, it fails to use the correct verb form. "Stressed" should be replaced with "stress" to maintain tense agreement.

In summary, sentences 1 and 2 are correct, while sentences 3 and 4 contain errors in verb tense agreement. The difference between sentences 1 and 2 lies in the presence or absence of "out," conveying slightly different levels of emphasis on avoiding stress.