English verb conjugation
CAN DULL

Regular verb: dull - dulled - dulled

Affirmation

Simple form	V-ing form
I can dull you can dull he can dull we can dull you can dull they can dull	I can be dulling you can be dulling he 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 he 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 he 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 can't dull you can't dull he can't dull we can't dull you can't dull they can't dull	I can't be dulling you can't be dulling he can't be dulling we can't be dulling you can't be dulling they can't be dulling
Perfect	V-ing perfect
I can't have dulled you can't have dulled he can't have dulled we can't have dulled you can't have dulled they can't have dulled	I can't have been dulling you can't have been dulling he can't have been dulling we can't have been dulling you can't have been dulling they can't have been dulling

Interrogative form

Simple form	V-ing form
can I dull? can you dull? can he dull? can we dull? can you dull? can they dull?	can I be dulling? can you be dulling? can he 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 he 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 he 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't I dull? can't you dull? can't he dull? can't we dull? can't you dull? can't they dull?	can't I be dulling? can't you be dulling? can't he be dulling? can't we be dulling? can't you be dulling? can't they be dulling?
Perfect	V-ing perfect
can't I have dulled? can't you have dulled? can't he have dulled? can't we have dulled? can't you have dulled? can't they have dulled?	can't I have been dulling? can't you have been dulling? can't he have been dulling? can't we have been dulling? can't you have been dulling? can't they have been dulling?