Learn Hardcore Chinese: nǐ jīntiān zhème lèi, gāi zǎodiǎnr shuìjiào le. - You’re so tired today; you should go to bed earlier.

Breakdown of nǐ jīntiān zhème lèi, gāi zǎodiǎnr shuìjiào le.

Used at the end of a sentence. Marks a change of state or new situation.

Why is there no 是 before 累?

In Mandarin, many adjectives can function as predicates by themselves, so you do not need a verb like to be in the same way English does.

So:

Here, 累 is acting like the main predicate of the clause.
Using 是累 would sound wrong in normal Mandarin.

What does 这么 mean here?

这么 means something like so, this much, or to such a degree.

In this sentence:

It emphasizes the degree of tiredness.

A useful pattern is:

Examples:

In your sentence, 这么累 means so tired, not just tired.

Could I use 很累 instead of 这么累?