English verb conjugation
COULD ESTIMATE

Regular verb: estimate - estimated - estimated

Affirmation

Simple form	V-ing form
I could estimate you could estimate he could estimate we could estimate you could estimate they could estimate	I could be estimating you could be estimating he could be estimating we could be estimating you could be estimating they could be estimating
Perfect	V-ing perfect
I could have estimated you could have estimated he could have estimated we could have estimated you could have estimated they could have estimated	I could have been estimating you could have been estimating he could have been estimating we could have been estimating you could have been estimating they could have been estimating

Negation

Simple form	V-ing form
I could not estimate you could not estimate he could not estimate we could not estimate you could not estimate they could not estimate	I could not be estimating you could not be estimating he could not be estimating we could not be estimating you could not be estimating they could not be estimating
Perfect	V-ing perfect
I could not have estimated you could not have estimated he could not have estimated we could not have estimated you could not have estimated they could not have estimated	I could not have been estimating you could not have been estimating he could not have been estimating we could not have been estimating you could not have been estimating they could not have been estimating

Interrogative form

Simple form	V-ing form
could I estimate? could you estimate? could he estimate? could we estimate? could you estimate? could they estimate?	could I be estimating? could you be estimating? could he be estimating? could we be estimating? could you be estimating? could they be estimating?
Perfect	V-ing perfect
could I have estimated? could you have estimated? could he have estimated? could we have estimated? could you have estimated? could they have estimated?	could I have been estimating? could you have been estimating? could he have been estimating? could we have been estimating? could you have been estimating? could they have been estimating?

Interro-negative form

Simple form	V-ing form
could I not estimate? could you not estimate? could he not estimate? could we not estimate? could you not estimate? could they not estimate?	could I not be estimating? could you not be estimating? could he not be estimating? could we not be estimating? could you not be estimating? could they not be estimating?
Perfect	V-ing perfect
could I not have estimated? could you not have estimated? could he not have estimated? could we not have estimated? could you not have estimated? could they not have estimated?	could I not have been estimating? could you not have been estimating? could he not have been estimating? could we not have been estimating? could you not have been estimating? could they not have been estimating?