Present Simple:
Use the present simple for habits and things that do not change.

Structure:
I walk / you walk / he walks / she walks / it walks / we walk / you walk / they walk

Negative
I do not walk / you do not walk / he does not walk / she does not walk / it does not walk / we do not walk / you do not walk / they do not walk

Interrogative
do I walk? / do you walk? / does he walk? / does she walk? / does it walk? / do we walk? / do you walk? / do they walk?

Contraction
do not = don't
does not = doesn't

Examples:

Shanghai is in China.
I work at IBM.
I eat at the restaurant.
I don't eat at home for lunch.
Do you eat in restaurants?