English verb conjugation
CAN TOUGH

Regular verb: tough - toughed - toughed

Affirmation

Simple form	V-ing form
I can tough you can tough he can tough we can tough you can tough they can tough	I can be toughing you can be toughing he can be toughing we can be toughing you can be toughing they can be toughing
Perfect	V-ing perfect
I can have toughed you can have toughed he can have toughed we can have toughed you can have toughed they can have toughed	I can have been toughing you can have been toughing he can have been toughing we can have been toughing you can have been toughing they can have been toughing

Negation

Simple form	V-ing form
I can't tough you can't tough he can't tough we can't tough you can't tough they can't tough	I can't be toughing you can't be toughing he can't be toughing we can't be toughing you can't be toughing they can't be toughing
Perfect	V-ing perfect
I can't have toughed you can't have toughed he can't have toughed we can't have toughed you can't have toughed they can't have toughed	I can't have been toughing you can't have been toughing he can't have been toughing we can't have been toughing you can't have been toughing they can't have been toughing

Interrogative form

Simple form	V-ing form
can I tough? can you tough? can he tough? can we tough? can you tough? can they tough?	can I be toughing? can you be toughing? can he be toughing? can we be toughing? can you be toughing? can they be toughing?
Perfect	V-ing perfect
can I have toughed? can you have toughed? can he have toughed? can we have toughed? can you have toughed? can they have toughed?	can I have been toughing? can you have been toughing? can he have been toughing? can we have been toughing? can you have been toughing? can they have been toughing?

Interro-negative form

Simple form	V-ing form
can't I tough? can't you tough? can't he tough? can't we tough? can't you tough? can't they tough?	can't I be toughing? can't you be toughing? can't he be toughing? can't we be toughing? can't you be toughing? can't they be toughing?
Perfect	V-ing perfect
can't I have toughed? can't you have toughed? can't he have toughed? can't we have toughed? can't you have toughed? can't they have toughed?	can't I have been toughing? can't you have been toughing? can't he have been toughing? can't we have been toughing? can't you have been toughing? can't they have been toughing?