This is the 3340th most frequent French word.
écrire
To write.
In this sentence, 'écrire' is used in the infinitive form to indicate the future action of writing.
Je vais écrire une lettre à mon ami.
I am going to write a letter to my friend.
Here, 'écrit' is the conjugated form of 'écrire' in the present tense, describing the way he performs the writing action.
Il écrit très lentement.
He writes very slowly.
The word 'écrit' is the past participle of 'écrire', used here in the past perfect tense to denote a completed action.