I can nibble you can nibble she can nibble we can nibble you can nibble they can nibble
V-ing form
I can be nibbling you can be nibbling she can be nibbling we can be nibbling you can be nibbling they can be nibbling
Perfect
I can have nibbled you can have nibbled she can have nibbled we can have nibbled you can have nibbled they can have nibbled
V-ing perfect
I can have been nibbling you can have been nibbling she can have been nibbling we can have been nibbling you can have been nibbling they can have been nibbling
Negation
Simple form
I can't nibble you can't nibble she can't nibble we can't nibble you can't nibble they can't nibble
V-ing form
I can't be nibbling you can't be nibbling she can't be nibbling we can't be nibbling you can't be nibbling they can't be nibbling
Perfect
I can't have nibbled you can't have nibbled she can't have nibbled we can't have nibbled you can't have nibbled they can't have nibbled
V-ing perfect
I can't have been nibbling you can't have been nibbling she can't have been nibbling we can't have been nibbling you can't have been nibbling they can't have been nibbling
Interrogative form
Simple form
can I nibble? can you nibble? can she nibble? can we nibble? can you nibble? can they nibble?
V-ing form
can I be nibbling? can you be nibbling? can she be nibbling? can we be nibbling? can you be nibbling? can they be nibbling?
Perfect
can I have nibbled? can you have nibbled? can she have nibbled? can we have nibbled? can you have nibbled? can they have nibbled?
V-ing perfect
can I have been nibbling? can you have been nibbling? can she have been nibbling? can we have been nibbling? can you have been nibbling? can they have been nibbling?
Interro-negative form
Simple form
can't I nibble? can't you nibble? can't she nibble? can't we nibble? can't you nibble? can't they nibble?
V-ing form
can't I be nibbling? can't you be nibbling? can't she be nibbling? can't we be nibbling? can't you be nibbling? can't they be nibbling?
Perfect
can't I have nibbled? can't you have nibbled? can't she have nibbled? can't we have nibbled? can't you have nibbled? can't they have nibbled?
V-ing perfect
can't I have been nibbling? can't you have been nibbling? can't she have been nibbling? can't we have been nibbling? can't you have been nibbling? can't they have been nibbling?