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 cannot extend you cannot extend he cannot extend we cannot extend you cannot extend they cannot extend	I cannot be extending you cannot be extending he cannot be extending we cannot be extending you cannot be extending they cannot be extending
Perfect	V-ing perfect
I cannot have extended you cannot have extended he cannot have extended we cannot have extended you cannot have extended they cannot have extended	I cannot have been extending you cannot have been extending he cannot have been extending we cannot have been extending you cannot have been extending they cannot 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 I not extend? can you not extend? can he not extend? can we not extend? can you not extend? can they not extend?	can I not be extending? can you not be extending? can he not be extending? can we not be extending? can you not be extending? can they not be extending?
Perfect	V-ing perfect
can I not have extended? can you not have extended? can he not have extended? can we not have extended? can you not have extended? can they not have extended?	can I not have been extending? can you not have been extending? can he not have been extending? can we not have been extending? can you not have been extending? can they not have been extending?