"Der Mann und die Frau haben viele Kinder."

Translation: The man and the woman have a lot of children.

[juan2345usa]

When I mouse over the word "Frau" wife was one of the translations. Then why did I get a wrong answer?

[izygray]

Do not trust those translations that much. In several cases they are wrong but most of the time they are out of context and cannot be used.

[twiztedfate]

Frau can be Woman or wife. But it's pretty much always woman if it's just an article in front and wife if it's a possessive. But yes The hover translations are just a guideline you can't solely go off of them

[VaterGut]

why can Frau not be wife here? Must Frau (woman) be 'possessed' (in the possessive) in order to be a wife..?

[vikukunta]

Duolingo probably expects either husband and wife or man and woman

[Bob_Dean]

Strictly speaking, you have a lot of 'stuff (eg sugar)' but you have many children; If it's countable then it's many / If it's measurable (by weight or volume) it's much or a lot.