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