English verb conjugation
CAN DULL

Regular verb: dull - dulled - dulled

Affirmation

Simple form	V-ing form
I can dull you can dull she can dull we can dull you can dull they can dull	I can be dulling you can be dulling she can be dulling we can be dulling you can be dulling they can be dulling
Perfect	V-ing perfect
I can have dulled you can have dulled she can have dulled we can have dulled you can have dulled they can have dulled	I can have been dulling you can have been dulling she can have been dulling we can have been dulling you can have been dulling they can have been dulling

Negation

Simple form	V-ing form
I cannot dull you cannot dull she cannot dull we cannot dull you cannot dull they cannot dull	I cannot be dulling you cannot be dulling she cannot be dulling we cannot be dulling you cannot be dulling they cannot be dulling
Perfect	V-ing perfect
I cannot have dulled you cannot have dulled she cannot have dulled we cannot have dulled you cannot have dulled they cannot have dulled	I cannot have been dulling you cannot have been dulling she cannot have been dulling we cannot have been dulling you cannot have been dulling they cannot have been dulling

Interrogative form

Simple form	V-ing form
can I dull? can you dull? can she dull? can we dull? can you dull? can they dull?	can I be dulling? can you be dulling? can she be dulling? can we be dulling? can you be dulling? can they be dulling?
Perfect	V-ing perfect
can I have dulled? can you have dulled? can she have dulled? can we have dulled? can you have dulled? can they have dulled?	can I have been dulling? can you have been dulling? can she have been dulling? can we have been dulling? can you have been dulling? can they have been dulling?

Interro-negative form

Simple form	V-ing form
can I not dull? can you not dull? can she not dull? can we not dull? can you not dull? can they not dull?	can I not be dulling? can you not be dulling? can she not be dulling? can we not be dulling? can you not be dulling? can they not be dulling?
Perfect	V-ing perfect
can I not have dulled? can you not have dulled? can she not have dulled? can we not have dulled? can you not have dulled? can they not have dulled?	can I not have been dulling? can you not have been dulling? can she not have been dulling? can we not have been dulling? can you not have been dulling? can they not have been dulling?