English verb conjugation
COULD ALERT

Regular verb: alert - alerted - alerted

Affirmation

Simple form	V-ing form
I could alert you could alert she could alert we could alert you could alert they could alert	I could be alerting you could be alerting she could be alerting we could be alerting you could be alerting they could be alerting
Perfect	V-ing perfect
I could have alerted you could have alerted she could have alerted we could have alerted you could have alerted they could have alerted	I could have been alerting you could have been alerting she could have been alerting we could have been alerting you could have been alerting they could have been alerting

Negation

Simple form	V-ing form
I couldn't alert you couldn't alert she couldn't alert we couldn't alert you couldn't alert they couldn't alert	I couldn't be alerting you couldn't be alerting she couldn't be alerting we couldn't be alerting you couldn't be alerting they couldn't be alerting
Perfect	V-ing perfect
I couldn't have alerted you couldn't have alerted she couldn't have alerted we couldn't have alerted you couldn't have alerted they couldn't have alerted	I couldn't have been alerting you couldn't have been alerting she couldn't have been alerting we couldn't have been alerting you couldn't have been alerting they couldn't have been alerting

Interrogative form

Simple form	V-ing form
could I alert? could you alert? could she alert? could we alert? could you alert? could they alert?	could I be alerting? could you be alerting? could she be alerting? could we be alerting? could you be alerting? could they be alerting?
Perfect	V-ing perfect
could I have alerted? could you have alerted? could she have alerted? could we have alerted? could you have alerted? could they have alerted?	could I have been alerting? could you have been alerting? could she have been alerting? could we have been alerting? could you have been alerting? could they have been alerting?

Interro-negative form

Simple form	V-ing form
couldn't I alert? couldn't you alert? couldn't she alert? couldn't we alert? couldn't you alert? couldn't they alert?	couldn't I be alerting? couldn't you be alerting? couldn't she be alerting? couldn't we be alerting? couldn't you be alerting? couldn't they be alerting?
Perfect	V-ing perfect
couldn't I have alerted? couldn't you have alerted? couldn't she have alerted? couldn't we have alerted? couldn't you have alerted? couldn't they have alerted?	couldn't I have been alerting? couldn't you have been alerting? couldn't she have been alerting? couldn't we have been alerting? couldn't you have been alerting? couldn't they have been alerting?