I could interfere you could interfere she could interfere we could interfere you could interfere they could interfere
V-ing form
I could be interfering you could be interfering she could be interfering we could be interfering you could be interfering they could be interfering
Perfect
I could have interfered you could have interfered she could have interfered we could have interfered you could have interfered they could have interfered
V-ing perfect
I could have been interfering you could have been interfering she could have been interfering we could have been interfering you could have been interfering they could have been interfering
Negation
Simple form
I couldn't interfere you couldn't interfere she couldn't interfere we couldn't interfere you couldn't interfere they couldn't interfere
V-ing form
I couldn't be interfering you couldn't be interfering she couldn't be interfering we couldn't be interfering you couldn't be interfering they couldn't be interfering
Perfect
I couldn't have interfered you couldn't have interfered she couldn't have interfered we couldn't have interfered you couldn't have interfered they couldn't have interfered
V-ing perfect
I couldn't have been interfering you couldn't have been interfering she couldn't have been interfering we couldn't have been interfering you couldn't have been interfering they couldn't have been interfering
Interrogative form
Simple form
could I interfere? could you interfere? could she interfere? could we interfere? could you interfere? could they interfere?
V-ing form
could I be interfering? could you be interfering? could she be interfering? could we be interfering? could you be interfering? could they be interfering?
Perfect
could I have interfered? could you have interfered? could she have interfered? could we have interfered? could you have interfered? could they have interfered?
V-ing perfect
could I have been interfering? could you have been interfering? could she have been interfering? could we have been interfering? could you have been interfering? could they have been interfering?
Interro-negative form
Simple form
couldn't I interfere? couldn't you interfere? couldn't she interfere? couldn't we interfere? couldn't you interfere? couldn't they interfere?
V-ing form
couldn't I be interfering? couldn't you be interfering? couldn't she be interfering? couldn't we be interfering? couldn't you be interfering? couldn't they be interfering?
Perfect
couldn't I have interfered? couldn't you have interfered? couldn't she have interfered? couldn't we have interfered? couldn't you have interfered? couldn't they have interfered?
V-ing perfect
couldn't I have been interfering? couldn't you have been interfering? couldn't she have been interfering? couldn't we have been interfering? couldn't you have been interfering? couldn't they have been interfering?