1. Do / Does / Don’t / Doesn’t
Simple Present Tense
Do / Does / Don’t / Doesn’t

2. Affirmative I study mathematics. You study mathematics.
He studies mathematics.
She studies mathematics.
It studies mathematics.
We study mathematics.
They study mathematics.
Subject + Verb + Complement

3. Grammar Rules He fishes at the sea. She kisses to her boyfriend.
Verbs ending: "SS", "SH", "CH", "O" and "X" 
He fishes  at the sea.
She kisses  to her boyfriend.
He watches  the mountain.
He fixes  his car.
She goes  to the office.
Subject + Verb + Complement

4. Grammar Rules She tries to be better. She studies for her exam.
Verbs ending: Consonant + Y
She tries  to be better.
She studies  for her exam.
He flies  in the sky.
He tidies  his bedroom.
He spies  me.
try
study
fly
tidy
spy
Subject + Verb + Complement

5. Grammar Rules She buys a car. She pays for the taxi.
Verbs ending: Vowel + Y
She buys  a car.
She pays  for the taxi.
He plays  the guitar.
He enjoys  playing tennis.
He says  to me.
Subject + Verb + Complement

6. Negative Aux. →inf. Verb. I don’t play drums. You don’t play drums.
He doesn’t play drums.
She doesn’t play drums.
It doesn’t play drums.
We don’t play drums.
They don’t play drums.
Subject + Don’t/Doesn’t + Verb [inf]+ Complement

7. Grammar Rules Aux. → inf. Verb. I don't play tennis.
Do + Not = Don’t Does + Not = Doesn’t 
I  don't  play tennis.
He  doesn't  work in an office.
They  don't  travel to Santiago.
I  do not play tennis.
He  does not  work in an office.
They  do not  travel to Santiago.
Subject + Don’t/Doesn’t + Verb [inf]+ Complement

8. Interrogative Aux. →inf. verb. Do I go to work ? Do You go to work ?
Does He go to work ?
Does She go to work ?
Does It go to work ?
Do We go to work ?
Do They go to work ?
Do/Does + Subject + Verb [Inf] + Complement ?

9. Grammar Rules Do you work on Sundays? What does he do on Saturday?
Aux. → inf. verb
Affirmative and Negative questions 
Do you work on Sundays?
What does he do on Saturday?
Don’t you come here on Saturdays?
Why doesn’t she talk with us?
Do/Does + Subject + Verb [Inf] + Complement ?
Wh + Do/Does + Subject + Verb [Inf] + Complement ?

10. Do / Does / Don’t / Doesn’t
Simple Present Tense
Do / Does / Don’t / Doesn’t
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