1. Thank you so much for not telling her the truth.

2. Thank you so much for not having told her the truth.
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Which one is grammatical? Are both OK? Which one is commonly used?

3 answers

The first sentence is grammatical and commonly used.
Thank you for your help.
Isn't #2 grammatical?

What about the following?
Which one is correct?

3. I heard that you had not told her the truth.

4. I heard that you didn't tell her the truth.
Sentence 2 is grammatical, but awkward. I can't think of any situation when this would be necessary.

Both 3 and 4 are correct. However, 4 is more commonly used.