How do you say I miss my friend in French?

There are a few ways to say "I miss my friend" in French, depending on the level of formality and the specific nuance you want to convey. Here are some options:

Formal:

* Je me sens triste de ne pas voir mon ami/mamie. (I feel sad not seeing my friend)

* J'ai beaucoup de regrets de ne pas pouvoir voir mon ami/mamie. (I deeply regret not being able to see my friend)

Informal:

* Je pense beaucoup à mon ami/mamie. (I think about my friend a lot)

* Il me manque mon ami/mamie. (I miss my friend)

* J'aimerais tellement voir mon ami/mamie. (I would love to see my friend)

* J'ai envie de voir mon ami/mamie. (I want to see my friend)

You can also add specific details to make your sentence more personal, like:

* Je pense beaucoup à tous les bons moments qu'on a passés ensemble. (I think a lot about all the good times we had together)

* J'aimerais bien lui parler. (I would like to talk to him/her)

Remember to adjust the gender of the pronoun "mon" (my) to match the gender of your friend.