The basic form of the simple present is the same as the base form of the verb, unless the subject is third person singular, in which case a form with the addition of -(e)s is used. For details of how to make this inflected form, see English verbs: Third-person singular present.
The copula verb be has irregular forms: am (first person singular), is (third person singular) and are (second person singular and all persons plural). The modal verbs (can, must, etc.) have only a single form, with no addition of -s for the third person singular.
The above refers to the indicative mood of the simple present; for the formation and use of the subjunctive mood, see English subjunctive. (The defective verb beware has no simple present indicative, although it can be used in the subjunctive.)
The present simple of lexical verbs has an expanded form which uses do (or does, in the third person indicative) as an auxiliary verb. This is used particularly when forming questions and other clauses requiring inversion, negated clauses with not, and clauses requiring emphasis. For details see do-support. For the verbs (auxiliary and copular) which do not make this form, as well as the formation and use of contracted forms such as 's, isn't and don't, see English auxiliaries and contractions.
All forms of the simple present are given below, using the verb write as an example:
Basic simple present indicative:
I write
You write
He/she/it writes
We write
You write
They write
Expanded simple present indicative (with question, negative, and negative question forms):
I do write (Do I write? I do not/don't write. Don't I/Do I not write?)
You do write (Do you write? You do not/don't write. Don't you/Do you not write?)
He/she/it does write (Does he write? He does not/doesn't write. Doesn't he/Does he not write?)
We/you/they do write (Do we write? We do not/don't write. Don't we/Do we not write?)
Simple present subjunctive (affirmative):
(that) I/you/he/she/it/we/they write
Simple present subjunctive, negative:
(that) I/you/he/she/it/we/they not write
Uses ---> The principal uses of the simple present are listed below.
To refer to an action or event that takes place habitually. In the other hand to remark habits, general realities, repeated actions or unchanging situations, emotions and wishes.[1] Such uses are often accompanied by frequency adverbs and adverbial phrases such as always, sometimes, often, usually, from time to time, rarely and never. Examples:
I always take a shower.
I never go to the cinema.
I walk to the pool.
He writes for a living.
She understands English.