I can estimate you can estimate he can estimate we can estimate you can estimate they can estimate
V-ing form
I can be estimating you can be estimating he can be estimating we can be estimating you can be estimating they can be estimating
Perfect
I can have estimated you can have estimated he can have estimated we can have estimated you can have estimated they can have estimated
V-ing perfect
I can have been estimating you can have been estimating he can have been estimating we can have been estimating you can have been estimating they can have been estimating
Negation
Simple form
I can't estimate you can't estimate he can't estimate we can't estimate you can't estimate they can't estimate
V-ing form
I can't be estimating you can't be estimating he can't be estimating we can't be estimating you can't be estimating they can't be estimating
Perfect
I can't have estimated you can't have estimated he can't have estimated we can't have estimated you can't have estimated they can't have estimated
V-ing perfect
I can't have been estimating you can't have been estimating he can't have been estimating we can't have been estimating you can't have been estimating they can't have been estimating
Interrogative form
Simple form
can I estimate? can you estimate? can he estimate? can we estimate? can you estimate? can they estimate?
V-ing form
can I be estimating? can you be estimating? can he be estimating? can we be estimating? can you be estimating? can they be estimating?
Perfect
can I have estimated? can you have estimated? can he have estimated? can we have estimated? can you have estimated? can they have estimated?
V-ing perfect
can I have been estimating? can you have been estimating? can he have been estimating? can we have been estimating? can you have been estimating? can they have been estimating?
Interro-negative form
Simple form
can't I estimate? can't you estimate? can't he estimate? can't we estimate? can't you estimate? can't they estimate?
V-ing form
can't I be estimating? can't you be estimating? can't he be estimating? can't we be estimating? can't you be estimating? can't they be estimating?
Perfect
can't I have estimated? can't you have estimated? can't he have estimated? can't we have estimated? can't you have estimated? can't they have estimated?
V-ing perfect
can't I have been estimating? can't you have been estimating? can't he have been estimating? can't we have been estimating? can't you have been estimating? can't they have been estimating?