All alike, both: đều before the verb

Đều means "all" or "both", but it goes before the verb or describing word, not next to the noun: Ba mẹ em đều là giáo viên. My parents are both teachers. Hai cái áo này đều đẹp. Both of these shirts are nice. It says that what's true of one is true of each of them.

The group comes first, then đều, then what they all do or are. Đều often teams up with tất cả (all) or các in front of the noun: Tất cả đều đồng ý. Everyone agreed. For two, the usual partner is cả hai (both of them): Cả hai đều đẹp. Both are nice. In English "all" can sit by the noun or after "are"; in Vietnamese, tất cả goes before the noun and đều before the verb, and you can use both.

The things can also come first, with the person after: Phở với bún, em đều thích. I like both phở and bún.

With không, đều comes first: Tụi nó đều không biết. None of them know.

Compare cũng (also, too), which links to someone or something else: Em cũng thích. I like it too. Đều is about everyone in the group at once.