How do you say are very pretty in Russian?

There are a few ways to say "are very pretty" in Russian, depending on the context and level of formality:

Formal:

* Вы очень красивы. (Vy ochen' krasivy) - This is the most formal way to say it, and is appropriate for addressing someone you don't know well or someone older than you.

* Вы очень привлекательны. (Vy ochen' privlekatel'ny) - This is a slightly more formal way to say "you are very attractive," which can be used as a more subtle compliment.

Informal:

* Ты очень красивая. (Ty ochen' krasivaya) - This is a more informal and casual way to say it, suitable for friends or someone you are close to.

* Ты очень симпатичная. (Ty ochen' simpatichnaya) - This is a more casual and friendly way to say "you are very pretty."

Note: The word "красавица" (krasavitsa) literally means "beautiful woman" and is a very strong compliment. It is best used only for women you know well and are comfortable with.

Remember to adjust the formality of your speech based on the situation and your relationship with the person you are speaking to.