Using よく with negative verbs

Question

Would the sentence 牛肉はよく食べません。/ I don't eat beef often. be:

1. grammatically incorrect because よく is used only in affirmative sentences?
2. grammatically correct, but unnatural (Using あまり would be preferable)?
3. perfectly acceptable?

Online searches led me to one site that used よく with a negative verb; others said that the use is unnatural; and most used it only with affirmative verbs, without comment on its use in this context.

Answer 1

I would say 2. Practically よく (in the sense of often) appears mostly in non-negative sentences, but strictly speaking, I don't think there is any word whose use in negative/affirmative sentences lead to ungrammaticality.

• 牛肉あまり食べません

is natural for simply not often. Another possibility is

• 牛肉をよくは食べません

which sounds denying to eat beef often (It is not the case that I eat beef often).

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よく in another sense can appear in negative sentences.

• よく飽きないな How come you don't get bored?

See this question for this usage.

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In the western dialect (kansai-ben), there is a pattern よう+V+ん＝cannot V. E.g., ようせん=can't do, よう言わん=can't say. (source); よう is a version of よく.