I urgently need help with a couple of sentences. Can you also check my previous post. I need to prepare the letter for tomorrow. Thank you.

1) The lady at the bottom left of the photo (is "in" the bottom a mistake when describing a photo?)
2) How long is it since you knew Peter?
(Wrong: I believe the only possible sentence is: How long have you known Peter?)
3) She is wearing a jacket with a long silk dress under it (underneath is a mistake?)

1) When describing a photo, it is more common to say "at the bottom left of the photo" instead of "in the bottom left of the photo." This is because "in" suggests being physically present inside something, whereas "at" suggests a specific location or position. So, in this case, it would be more appropriate to say "The lady at the bottom left of the photo."

2) Your correction is indeed accurate. The sentence "How long is it since you knew Peter?" is not grammatically correct. Instead, you can use the correct sentence: "How long have you known Peter?" This sentence follows the correct grammar structure for discussing the length of time someone has known another person.

3) While "underneath" is not necessarily a mistake, it is more common to say "under" in this context. So, you can say "She is wearing a jacket with a long silk dress under it." This sentence conveys the same meaning and is more commonly used when describing clothing layers.