1a) PRESENT INDEFINITE/SIMPLE
I write a letter.
She makes a doll.
Note:Use s/es with the 1st form of the verb if the Subject is He/She/It or singular Noun (boy, player, teacher, Mohan, Sita etc).
We do not write poems.
Ram does not play football.
Do you go to market?
Does he go for a walk?
Int. & Neg.: Do/Does+sub+not+V1
Do we not work?
1b) PRESENT CONTINUOUS
Mohan is reading.
Negative: Sub+is/am/are+not +V1+ing
They are not playing cricket.
Is he going?
Int. & Neg.: Is/Am/Are+sub+not+V1+ing
Are you not playing cricket?
1c) PRESENT PERFECT
She has made tea.
They have not taken medicine.
He has not come since Monday.
Have they slept?
Int. & Neg.: Has/Have+sub+not+V3
Have you not done your home-work?
1d) PRESENT PERFECT CONTINUOUS
I have been reading since 5 O’clock.
Neg.:Sub+has/have+not+been+V1+ ing+ Since/for
Ravi has not been playing since evening.
Have you been working for ten minutes?
Int. & Neg.:Has/Have+sub+not+been+VI+ing+since/for
Has she not been praying for five minutes?
Since: (For point of time) 10am, 6 O’clock, morning, 21st May, January,2002, when, then, yesterday, last year/month etc.
For: (For period of time) 2 days, 4 minutes, 2 hours, 7 months, 3 years, many days/months etc.
Note: Since or for is also used in perfect tense.