good-mannered??

Is it grammatically correct to say "he's good-mannered"?
I think that "He has good manners" is alright, but i'm not sure about the other one.
If one says "he's well-behaved", why one can't say "he's well-mannered"?
As you can see, I'm confused...

Good-mannered sounds really weird. I've never heard it before, I've only heard "well-mannered." Who told you you can't say that? That's really the only way I've ever heard it.

"Well-mannered" is probably used more than "he has good manners" which seems unnecessarily long-winded :-P

Good-mannered is grammatically incorrect because good is an adjective and you need a adverb as you're describing a verb (i.e. mannered.)
The adverb for good is well.
So well-mannered is the correct one whereas good-mannered is just wrong.

It IS well-mannered, not good-mannered.

American women are well-mannered! Just a random observation!

<<Good-mannered is grammatically incorrect because good is an adjective and you need a adverb as you're describing a verb (i.e. mannered.)
The adverb for good is well.
So well-mannered is the correct one whereas good-mannered is just wrong.>>

Oohh, this a very useful information! Haven't thought about it.
Thanks!!^^

SOUTHERN American women are well-mannered :-)

Did I cross the line?

<Good-mannered is grammatically incorrect because good is an adjective and you need a adverb as you're describing a verb (i.e. mannered.)
The adverb for good is well.
So well-mannered is the correct one whereas good-mannered is just wrong.>

manner is a noun not a verb. In this case the -ed suffix is an adjective suffix not a verb suffix (compare talent - talented).

we have:

to have a good heart - to be good-hearted
to have good humour - to be good-humoured
to have a good nature - to be good-natured
to have a good temper - to be good-tempered

Where the noun is qualified with good and then the -ed suffix is added.

to have good manners - to be well-mannered
would seem to break this pattern particularly since we also say

to have bad manners - to be bad-mannered
rather than to be badly-mannered.

In the case of well- the verb is put in past participle to form a passive: 'to be adjusted' and then prefixed with well- :

to be adjusted - to be well-adjusted
to be balanced - to be well-balanced
to be built - to be well-built
to be chosen - to be well-chosen
to be defined - to be well-defined
to be earned - to be well-earned
to be fed - to be well-fed
to be groomed - to be well-groomed
to be heeled - to be well-heeled
to be informed - to be well-informed
to be known to be well known
to be liked - to be well-liked
to be matched - to be well-matched
to be oiled - to be well-oiled
to be preserved - to be well-preserved
to be qualified - to be well-qualified
to be read - to be well-read
to be spoken - to be well-spoken
to be thought-of - to be well-thought-of
to be versed - to be well-versed
to be worn - to be well-worn