Irregular past
Present perfect
Superlative
1st conditional
2nd conditional
100

drink

drank

100

I forget

I have forgotten

100

big

biggest

100

rains tomorrow / stay home

If it rains tomorrow we will stay home.

100

know she lives / visit

If I knew where she lived, I would visit her.

200

fall

fell

200

We see

We have seen

200

thin

thinnest

200

study hard / pass 

If you study hard, you will pass the test.

200

you love me / ask marry

If you loved me, you would ask me to marry you.

300

know

knew

300

They grow

They have grown

300

fantastic

the most fantastic

300

have time / finish homework

If I have time, I'll finish my homework.

300

I rich / buy new house

If I were rich, I would buy a new house.

400

understand

understood

400

He bites

He has bitten

400

intelligent

the most intelligent

400

drop glass / break

If you drop that glass, it will break.

400

go bed earlier / not so tired

If you went to bed earlier, you wouldn't be so tired.

500
kneel

knelt

500

She sews

She has sewn

500

itchy

itchiest

500

do / miss plane ?

What will you do if you miss the plane?

500

I prime minister / improve health care

If I were prime minister, I would improve health care.