PRESENT SIMPLE

Form.
The present simple is formed with a subject (I, Paul, the students, etc.) and a main verb (eat, read, drink, etc.).
In affirmative sentences, we add to the main verb the ending -s in the third person singular (he, she, it).

Verbs ending in -ss, -ch, -sh, -x, -o take the ending -es.

Examples: kiss-kisses                  touch-touches               mix-mixes

If a verb ends in -y preceded by a consonant, the -y is replaced by the ending -ies

Examples: tidy-tidies           study-studies            cry-cries

But if the -y is preceded by a vowel, we add -s only.

Examples: buy-buys                    play-plays             enjoy-enjoys

Examples: I work in a bank
She works in a bookshop
In order to form a negation, we use does not (doesn´t) before the main verb of the third person singular and do not (don´t) before the main verb of the other persons.
Examples: I don´t eat fish.
He doesn´t eat fish.
In a negation, the main verb does not end in -s in the tird person singular.