Choose the correct answer. If I ... (be) you, I would go out tonight.

The correct answer is 'were'. This is a type 2 conditional sentence (also known as a second conditional) which is used to talk about unreal or improbable situations in the present or future. The structure is: If + past simple, would + infinitive. Therefore, the correct sentence is: 'If I were you, I would go out tonight.' Answer: were