—We use Simple Present tense to talk about actions that happen or are repeated as part of a routine or schedule, for habits or scientific facts.

Examples:
I play tennis.
She does not play tennis.
Does he play tennis?
The train leaves every morning at 8 AM.
The train does not leave at 9 AM.
When does the train usually leave?
She always forgets her purse.
He never forgets his wallet.
The Earth circles the Sun every twelve months

Form:

The form of the verb changes on Simple Present for 3rd person singular (He/She/It)

Example: I/You/We/They work/watch/fly/do.
                He/She/It works/watches/flies/does.

Spelling rules for He/She/It

• Most verbs: add –s         live     lives             buy        buys 
• —Verbs ending in –s, -sh, -ch add –es.     miss       misses                  search               searches 
• —Verbs ending in a consonant followed by –y; change the –y to –ies.     study          studies 
• Verbs such as do, go, have are irregular.    do      does           go     goes               have       has