I can estimate you can estimate she can estimate we can estimate you can estimate they can estimate
V-ing form
I can be estimating you can be estimating she can be estimating we can be estimating you can be estimating they can be estimating
Perfect
I can have estimated you can have estimated she 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 she can have been estimating we can have been estimating you can have been estimating they can have been estimating
Negation
Simple form
I cannot estimate you cannot estimate she cannot estimate we cannot estimate you cannot estimate they cannot estimate
V-ing form
I cannot be estimating you cannot be estimating she cannot be estimating we cannot be estimating you cannot be estimating they cannot be estimating
Perfect
I cannot have estimated you cannot have estimated she cannot have estimated we cannot have estimated you cannot have estimated they cannot have estimated
V-ing perfect
I cannot have been estimating you cannot have been estimating she cannot have been estimating we cannot have been estimating you cannot have been estimating they cannot have been estimating
Interrogative form
Simple form
can I estimate? can you estimate? can she estimate? can we estimate? can you estimate? can they estimate?
V-ing form
can I be estimating? can you be estimating? can she be estimating? can we be estimating? can you be estimating? can they be estimating?
Perfect
can I have estimated? can you have estimated? can she 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 she have been estimating? can we have been estimating? can you have been estimating? can they have been estimating?
Interro-negative form
Simple form
can I not estimate? can you not estimate? can she not estimate? can we not estimate? can you not estimate? can they not estimate?
V-ing form
can I not be estimating? can you not be estimating? can she not be estimating? can we not be estimating? can you not be estimating? can they not be estimating?
Perfect
can I not have estimated? can you not have estimated? can she not have estimated? can we not have estimated? can you not have estimated? can they not have estimated?
V-ing perfect
can I not have been estimating? can you not have been estimating? can she not have been estimating? can we not have been estimating? can you not have been estimating? can they not have been estimating?