[Supperman]

Of course!
I don't think it is good thing to drink at every your lesson in school, either.
After school. Only once.

If a person has enough knowledge of grammar and vocabulary, yet he/she can't speak well, he/she might be too cautious, thinking too much, and some kind of self-restriction might exist.
Thinking "not to make any grammatical errors", "not to speak in bad pronunciation" etc.

When such a person has some alcohol, he/she will find him/herself that he/she will be able to speak fluently without restriction.
Because he/she gets drunk and can not think too much.

Once experienced, he/she will get his/her self-confidence, he/she will learn how to speak, he/she will learn that it isn't necessary to think too much.

This was MY experience, so I thought it might be your help.

Anyway, I hope your lesson to become a happy one,
and have a nice day!