"This man is good."

Translation: Ten mężczyzna jest dobry.

[duolingopl6]

How about: ... to dobry? The little bird says it's wrong :(

[mihxal]

You could say: "Ten mężczyzna to dobry człowiek" but with an adjective you should use the verb "być".

[duolingopl6]

Ok thank you. I think I also forgot the "ten"

[KasiaBuzala05]

Is "pan" and "mężczyzna" not the same ? I use Pan more when speaking to Polish my family :/

[Jellei]

The word "pan" as a noun is generally difficult to explain. It's something between "a man" and "a gentleman". In some contexts it may sound rather childish. In some contexts it sounds polite.

Anyway, "Ten pan" is correct here. Added now.

[Ema1610]

What is the difference between dobry and dobrzy?

[Dynamosaurus]

dobry is singular masculine nominative, or singular inanimate accusative.
dobrzy is plural virile nominative.

[chintsipoo]

When do we the accusative "dobrego" as an adjective for animate masculine? Can we say Ten mężczyzna jest dobrego?

[Jellei]

Yes, "dobrego" is Animate masculine Accusative, but there's no Accusative in our sentence here. Accusative is used for the direct object of the sentence, so e.g. "I see a good man" is "Widzę dobrego mężczyznę".

"mężczyzna" and "dobrego" don't match each other in terms of case.