I could overdose you could overdose he could overdose we could overdose you could overdose they could overdose
V-ing form
I could be overdosing you could be overdosing he could be overdosing we could be overdosing you could be overdosing they could be overdosing
Perfect
I could have overdosed you could have overdosed he could have overdosed we could have overdosed you could have overdosed they could have overdosed
V-ing perfect
I could have been overdosing you could have been overdosing he could have been overdosing we could have been overdosing you could have been overdosing they could have been overdosing
Negation
Simple form
I couldn't overdose you couldn't overdose he couldn't overdose we couldn't overdose you couldn't overdose they couldn't overdose
V-ing form
I couldn't be overdosing you couldn't be overdosing he couldn't be overdosing we couldn't be overdosing you couldn't be overdosing they couldn't be overdosing
Perfect
I couldn't have overdosed you couldn't have overdosed he couldn't have overdosed we couldn't have overdosed you couldn't have overdosed they couldn't have overdosed
V-ing perfect
I couldn't have been overdosing you couldn't have been overdosing he couldn't have been overdosing we couldn't have been overdosing you couldn't have been overdosing they couldn't have been overdosing
Interrogative form
Simple form
could I overdose? could you overdose? could he overdose? could we overdose? could you overdose? could they overdose?
V-ing form
could I be overdosing? could you be overdosing? could he be overdosing? could we be overdosing? could you be overdosing? could they be overdosing?
Perfect
could I have overdosed? could you have overdosed? could he have overdosed? could we have overdosed? could you have overdosed? could they have overdosed?
V-ing perfect
could I have been overdosing? could you have been overdosing? could he have been overdosing? could we have been overdosing? could you have been overdosing? could they have been overdosing?
Interro-negative form
Simple form
couldn't I overdose? couldn't you overdose? couldn't he overdose? couldn't we overdose? couldn't you overdose? couldn't they overdose?
V-ing form
couldn't I be overdosing? couldn't you be overdosing? couldn't he be overdosing? couldn't we be overdosing? couldn't you be overdosing? couldn't they be overdosing?
Perfect
couldn't I have overdosed? couldn't you have overdosed? couldn't he have overdosed? couldn't we have overdosed? couldn't you have overdosed? couldn't they have overdosed?
V-ing perfect
couldn't I have been overdosing? couldn't you have been overdosing? couldn't he have been overdosing? couldn't we have been overdosing? couldn't you have been overdosing? couldn't they have been overdosing?