English verb conjugation
CAN TIER

Regular verb: tier - tiered - tiered

Affirmation

Simple form	V-ing form
I can tier you can tier he can tier we can tier you can tier they can tier	I can be tiering you can be tiering he can be tiering we can be tiering you can be tiering they can be tiering
Perfect	V-ing perfect
I can have tiered you can have tiered he can have tiered we can have tiered you can have tiered they can have tiered	I can have been tiering you can have been tiering he can have been tiering we can have been tiering you can have been tiering they can have been tiering

Negation

Simple form	V-ing form
I cannot tier you cannot tier he cannot tier we cannot tier you cannot tier they cannot tier	I cannot be tiering you cannot be tiering he cannot be tiering we cannot be tiering you cannot be tiering they cannot be tiering
Perfect	V-ing perfect
I cannot have tiered you cannot have tiered he cannot have tiered we cannot have tiered you cannot have tiered they cannot have tiered	I cannot have been tiering you cannot have been tiering he cannot have been tiering we cannot have been tiering you cannot have been tiering they cannot have been tiering

Interrogative form

Simple form	V-ing form
can I tier? can you tier? can he tier? can we tier? can you tier? can they tier?	can I be tiering? can you be tiering? can he be tiering? can we be tiering? can you be tiering? can they be tiering?
Perfect	V-ing perfect
can I have tiered? can you have tiered? can he have tiered? can we have tiered? can you have tiered? can they have tiered?	can I have been tiering? can you have been tiering? can he have been tiering? can we have been tiering? can you have been tiering? can they have been tiering?

Interro-negative form

Simple form	V-ing form
can I not tier? can you not tier? can he not tier? can we not tier? can you not tier? can they not tier?	can I not be tiering? can you not be tiering? can he not be tiering? can we not be tiering? can you not be tiering? can they not be tiering?
Perfect	V-ing perfect
can I not have tiered? can you not have tiered? can he not have tiered? can we not have tiered? can you not have tiered? can they not have tiered?	can I not have been tiering? can you not have been tiering? can he not have been tiering? can we not have been tiering? can you not have been tiering? can they not have been tiering?