English verb conjugation
CAN BACKFILL

Regular verb: backfill - backfilled - backfilled

Affirmation

Simple form	V-ing form
I can backfill you can backfill he can backfill we can backfill you can backfill they can backfill	I can be backfilling you can be backfilling he can be backfilling we can be backfilling you can be backfilling they can be backfilling
Perfect	V-ing perfect
I can have backfilled you can have backfilled he can have backfilled we can have backfilled you can have backfilled they can have backfilled	I can have been backfilling you can have been backfilling he can have been backfilling we can have been backfilling you can have been backfilling they can have been backfilling

Negation

Simple form	V-ing form
I can't backfill you can't backfill he can't backfill we can't backfill you can't backfill they can't backfill	I can't be backfilling you can't be backfilling he can't be backfilling we can't be backfilling you can't be backfilling they can't be backfilling
Perfect	V-ing perfect
I can't have backfilled you can't have backfilled he can't have backfilled we can't have backfilled you can't have backfilled they can't have backfilled	I can't have been backfilling you can't have been backfilling he can't have been backfilling we can't have been backfilling you can't have been backfilling they can't have been backfilling

Interrogative form

Simple form	V-ing form
can I backfill? can you backfill? can he backfill? can we backfill? can you backfill? can they backfill?	can I be backfilling? can you be backfilling? can he be backfilling? can we be backfilling? can you be backfilling? can they be backfilling?
Perfect	V-ing perfect
can I have backfilled? can you have backfilled? can he have backfilled? can we have backfilled? can you have backfilled? can they have backfilled?	can I have been backfilling? can you have been backfilling? can he have been backfilling? can we have been backfilling? can you have been backfilling? can they have been backfilling?

Interro-negative form

Simple form	V-ing form
can't I backfill? can't you backfill? can't he backfill? can't we backfill? can't you backfill? can't they backfill?	can't I be backfilling? can't you be backfilling? can't he be backfilling? can't we be backfilling? can't you be backfilling? can't they be backfilling?
Perfect	V-ing perfect
can't I have backfilled? can't you have backfilled? can't he have backfilled? can't we have backfilled? can't you have backfilled? can't they have backfilled?	can't I have been backfilling? can't you have been backfilling? can't he have been backfilling? can't we have been backfilling? can't you have been backfilling? can't they have been backfilling?