お酒 (alcohol) は多く (too much) ないですよ
For what need mattaku here?
全く is an adverb that puts emphasis on the adjective.
I wholeheartedly agree Duo.
Why can't it be あまり instead of まったく here?
Why is there is 多く? Cant use まったくない?
まったくない means there isn't any alcohol so it's wrong.
Because 全く is an adverb that enhances 多くない
よisn't the necessary part of this sentence,with or without it the whole idea doesn't change.
Well, no, not really. Just saying "There isn't a lot of alcohol" is a statement. "There isn't a lot of alcohol, you know" can be used to cide someone for overindulging, for instance.
I'd say お酒があまりではありませんよ should be acceptable as well.