What does よく do when used with ~のほうが?


> さあ、妻のほうがよく知っています。

What does よく do when used with ~のほうが? Is the よく required? What does it mean in
this context?




よく here means "well." It functions as an adverb. It's not required, but it
gives more insight about how "well" she knows about it.

> さあ、妻のほうがよく知っています。
>

>> Uh, my wife knows it well.

More context is needed for a better translation because using ほう implies a
two-sided comparison. Plus, we don't know whose wife she is, so I just
arbitrarily chose "my" for the translation.

Note that よく could also mean "often" depending on the context, see this
[thread](https://japanese.stackexchange.com/q/29267/45630) for more details.




> さあ、妻のほうがよく知っています。

would mean

> Well (I don't know), my wife knows it better (than I do).

「さあ」 can mean "now (let's...)", but it can also mean/imply "I don't know", eg
「これ何？」「さあね。」("What's this?" "Who knows.") So here it implies that the speaker
doesn't really know.

Regarding the 妻, one usually refers to one's wife as 妻, 家内, 嫁さん, うちのやつ etc.  
To refer to another's wife, one'd usually say (～の)奥さん.

よく means "(do something) _well_ ", so 妻がよく知っています would mean "My wife knows it
_well_ ".

～のほうが adds a meaning "do ... _compared to someone/something else_ ".  
So 妻のほうが知っています would mean "My wife knows, _compared to_ me." ⇒ "My wife knows
_better than_ I do."

> Is the よく required?

No, not really. 妻のほうが知っています would mean almost the same thing. よく might add a
nuance of "in detail", perhaps?

