Please check "I do not approve of alcohol".
"My parents do not/didn't/used not to approve of alcohol".
There is one more question. "How to stop being alcoholic". Does it mean the person is addicted and how can he
canstop takingdrinking alcohol"?
"I do not approve of alcohol" is grammatically correct but I wonder if it wouldn't be better as "I do not approve of drinking alcohol". I find it unnatural to actually disapprove of a substance. Presumably, you do not drink alcohol and you don't like people who do.
If your parents used not approve of [drinking] alcohol but now they do approve, then your sentence is fine. If their opinion has not changed, then just say "My parents don't approve of [drinking] alcohol." Most people will assume that that has always been their opinion.
"How to stop being alcoholic" doesn't work. A person is an alcoholic. The only thing that can stop being alcoholic is alcohol! I don't think you would have much success if you shouted at a bottle of wine "Stop being alcoholic!" Your sentence would only work if it was the title of a piece of writing or of a chapter in a book, ie:
How to stop being an alcoholic:
1. Recognise that you are an alcoholic.
2. Join AA.
3. Throw away all alcohol in your house.
If you want to ask a question, it would be "I think I'm an alcoholic. How can I stop drinking alcohol?" or something similar.
Student or Learner