The present

The verb forms are the present, the past and the past participle.

keep, kept, kept - zatrzymać

The present

May I keep it?.
Czy mogę to zatrzymać?.

The past

She kept a bottle of whisky under her bed.
Ona trzymała butelkę whisky pod łóżkiem.

The past participle

She has kept it.
Ona to zatrzymała.