"每...都..." (měi...dōu...) is a pattern used to express "every" when talking about a quantitative amount. This is similar to how we say "every day I eat cereal" or "every student passed the exam" in Chinese grammar.

Using 每...都 to mean "every" 
Using 每 and 都 together is pretty simple.

每+number+measure word+noun+都+Adjective/verb

Note is that if the number is simply just "one", then it's usually omitted.

Examples

Just make sure that when you went to express "every one" with 每, as in "every day I take a nap", don't forget the 都! Sometimes you don't necessarily need it, but when in doubt, just use it to be safe! 都 can also be used to say "both" if there are only two things being referenced. It's possible to think of this as being "all two" of something, even if that sounds somewhat weird in English. It's just how Chinese says "both", by using the same word that it uses for other, larger numbers as well.

Using 每 and 都 when focusing on a certain action

In this grammar structure, we focus on every time a certain action is done, like "every time he speaks I can't understand him."

每+verb+number+都+Adjective/verb

Examples