English verb conjugation
COULD ALERT

Regular verb: alert - alerted - alerted

Affirmation

Simple form	V-ing form
I could alert you could alert he could alert we could alert you could alert they could alert	I could be alerting you could be alerting he 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 he 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 he 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 he 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 he 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 he 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 he 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 he alert? could we alert? could you alert? could they alert?	could I be alerting? could you be alerting? could he 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 he 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 he 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 he 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 he 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 he 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 he have been alerting? couldn't we have been alerting? couldn't you have been alerting? couldn't they have been alerting?