Present simple

Or simple present.

Affirmative: I write; He writes
Negative: He does not write
Interrogative: Does he write?
Negative interrogative: Does he not write?
Note that the "simple present" in idiomatic English often identifies habitual or customary action:

He writes about beavers (understanding that he does so all of the time.)
It is used with stative verbs:

She thinks that beavers are remarkable
It can also have a future meaning (though much less commonly than in many other languages):

She goes to Milwaukee on Tuesday.
The present simple has an intensive or emphatic form with "do": He does write. In the negative and interrogative forms, of course, this is identical to the non-emphatic forms. It is typically used as a response to the question Does he write, whether that question is expressed or implied, and says that indeed, he does write.

The different syntactic behavior of the negative particle not and the negative inflectional suffix -n't in the interrogative form is also worth noting. In formal literary English of the sort in which contractions are avoided, not attaches itself to the main verb: Does he not write? When the colloquial contraction -n't is used, this attaches itself to the auxiliary do: Doesn't he write? This in fact is a contraction of a more archaic word order, still occasionally found in poetry: *Does not he write?