"The youth of today does not sleep in the morning."

Translation: A juventude de hoje não dorme de manhã.

[bananajello]

Why is this "de manhã" and not "na manhã"?

[Paulenrique]

In the morning = de manhã, pela manhã

[barbaratorrance]

the youth of today DONOT sleep in the morning THIS IS CORRECT ENGLISH

[duolingvisto]

Actually, you're right and you shouldn't have been downvoted.
The youth of today = They --> They do not sleep in the morning.

[bcsteve]

This sentence is awkward in English: "youth" is being used here as a collective noun, and although there's no concrete rule about collective nouns being singular or plural, in this case it would usually take the plural form. A more correct way of saying it would be "The youth of today DO not sleep in the morning".