English verb conjugation
CAN EXTEND

Regular verb: extend - extended - extended

Affirmation

Simple form	V-ing form
I can extend you can extend he can extend we can extend you can extend they can extend	I can be extending you can be extending he can be extending we can be extending you can be extending they can be extending
Perfect	V-ing perfect
I can have extended you can have extended he can have extended we can have extended you can have extended they can have extended	I can have been extending you can have been extending he can have been extending we can have been extending you can have been extending they can have been extending

Negation

Simple form	V-ing form
I can't extend you can't extend he can't extend we can't extend you can't extend they can't extend	I can't be extending you can't be extending he can't be extending we can't be extending you can't be extending they can't be extending
Perfect	V-ing perfect
I can't have extended you can't have extended he can't have extended we can't have extended you can't have extended they can't have extended	I can't have been extending you can't have been extending he can't have been extending we can't have been extending you can't have been extending they can't have been extending

Interrogative form

Simple form	V-ing form
can I extend? can you extend? can he extend? can we extend? can you extend? can they extend?	can I be extending? can you be extending? can he be extending? can we be extending? can you be extending? can they be extending?
Perfect	V-ing perfect
can I have extended? can you have extended? can he have extended? can we have extended? can you have extended? can they have extended?	can I have been extending? can you have been extending? can he have been extending? can we have been extending? can you have been extending? can they have been extending?

Interro-negative form

Simple form	V-ing form
can't I extend? can't you extend? can't he extend? can't we extend? can't you extend? can't they extend?	can't I be extending? can't you be extending? can't he be extending? can't we be extending? can't you be extending? can't they be extending?
Perfect	V-ing perfect
can't I have extended? can't you have extended? can't he have extended? can't we have extended? can't you have extended? can't they have extended?	can't I have been extending? can't you have been extending? can't he have been extending? can't we have been extending? can't you have been extending? can't they have been extending?