English verb conjugation
COULD NIBBLE

Regular verb: nibble - nibbled - nibbled

Affirmation

Simple form	V-ing form
I could nibble you could nibble she could nibble we could nibble you could nibble they could nibble	I could be nibbling you could be nibbling she could be nibbling we could be nibbling you could be nibbling they could be nibbling
Perfect	V-ing perfect
I could have nibbled you could have nibbled she could have nibbled we could have nibbled you could have nibbled they could have nibbled	I could have been nibbling you could have been nibbling she could have been nibbling we could have been nibbling you could have been nibbling they could have been nibbling

Negation

Simple form	V-ing form
I couldn't nibble you couldn't nibble she couldn't nibble we couldn't nibble you couldn't nibble they couldn't nibble	I couldn't be nibbling you couldn't be nibbling she couldn't be nibbling we couldn't be nibbling you couldn't be nibbling they couldn't be nibbling
Perfect	V-ing perfect
I couldn't have nibbled you couldn't have nibbled she couldn't have nibbled we couldn't have nibbled you couldn't have nibbled they couldn't have nibbled	I couldn't have been nibbling you couldn't have been nibbling she couldn't have been nibbling we couldn't have been nibbling you couldn't have been nibbling they couldn't have been nibbling

Interrogative form

Simple form	V-ing form
could I nibble? could you nibble? could she nibble? could we nibble? could you nibble? could they nibble?	could I be nibbling? could you be nibbling? could she be nibbling? could we be nibbling? could you be nibbling? could they be nibbling?
Perfect	V-ing perfect
could I have nibbled? could you have nibbled? could she have nibbled? could we have nibbled? could you have nibbled? could they have nibbled?	could I have been nibbling? could you have been nibbling? could she have been nibbling? could we have been nibbling? could you have been nibbling? could they have been nibbling?

Interro-negative form

Simple form	V-ing form
couldn't I nibble? couldn't you nibble? couldn't she nibble? couldn't we nibble? couldn't you nibble? couldn't they nibble?	couldn't I be nibbling? couldn't you be nibbling? couldn't she be nibbling? couldn't we be nibbling? couldn't you be nibbling? couldn't they be nibbling?
Perfect	V-ing perfect
couldn't I have nibbled? couldn't you have nibbled? couldn't she have nibbled? couldn't we have nibbled? couldn't you have nibbled? couldn't they have nibbled?	couldn't I have been nibbling? couldn't you have been nibbling? couldn't she have been nibbling? couldn't we have been nibbling? couldn't you have been nibbling? couldn't they have been nibbling?