Mange les fraises. Why not mangeZ les fraises.

[Truffaut]

I learned some time ago, when dabbling in French, that an imperative statement like, "Eat the strawberries!" was "addressed" to YOU, hence, should be "(vous--understood) mangez les fraises!"

But Duolingo is saying "Mange les fraises!" is correct. Anyone know why?

[wataya]

Both are correct. 'Mangez les fraises' is the formal (or 2nd person plural) imperative (vous) and 'mange les fraises' the informal one (tu). There is also a form including the speaker 'mangeons les fraises' ('Let's eat the strawberries).

[flaming]

Yes, the verb is "addressed" to YOU, but that does not mean that the verb form should match the one being addressed. The imperative form is not the same as the indicative form, but sometimes the two do coincide. See the "conjugation" chart for more info http://en.wiktionary.org/wiki/manger#French