English verb conjugation
CAN BUTTRESS

Regular verb: buttress - buttressed - buttressed

Affirmation

Simple form	V-ing form
I can buttress you can buttress he can buttress we can buttress you can buttress they can buttress	I can be buttressing you can be buttressing he can be buttressing we can be buttressing you can be buttressing they can be buttressing
Perfect	V-ing perfect
I can have buttressed you can have buttressed he can have buttressed we can have buttressed you can have buttressed they can have buttressed	I can have been buttressing you can have been buttressing he can have been buttressing we can have been buttressing you can have been buttressing they can have been buttressing

Negation

Simple form	V-ing form
I can't buttress you can't buttress he can't buttress we can't buttress you can't buttress they can't buttress	I can't be buttressing you can't be buttressing he can't be buttressing we can't be buttressing you can't be buttressing they can't be buttressing
Perfect	V-ing perfect
I can't have buttressed you can't have buttressed he can't have buttressed we can't have buttressed you can't have buttressed they can't have buttressed	I can't have been buttressing you can't have been buttressing he can't have been buttressing we can't have been buttressing you can't have been buttressing they can't have been buttressing

Interrogative form

Simple form	V-ing form
can I buttress? can you buttress? can he buttress? can we buttress? can you buttress? can they buttress?	can I be buttressing? can you be buttressing? can he be buttressing? can we be buttressing? can you be buttressing? can they be buttressing?
Perfect	V-ing perfect
can I have buttressed? can you have buttressed? can he have buttressed? can we have buttressed? can you have buttressed? can they have buttressed?	can I have been buttressing? can you have been buttressing? can he have been buttressing? can we have been buttressing? can you have been buttressing? can they have been buttressing?

Interro-negative form

Simple form	V-ing form
can't I buttress? can't you buttress? can't he buttress? can't we buttress? can't you buttress? can't they buttress?	can't I be buttressing? can't you be buttressing? can't he be buttressing? can't we be buttressing? can't you be buttressing? can't they be buttressing?
Perfect	V-ing perfect
can't I have buttressed? can't you have buttressed? can't he have buttressed? can't we have buttressed? can't you have buttressed? can't they have buttressed?	can't I have been buttressing? can't you have been buttressing? can't he have been buttressing? can't we have been buttressing? can't you have been buttressing? can't they have been buttressing?