I could backfit you could backfit he could backfit we could backfit you could backfit they could backfit
V-ing form
I could be backfiting you could be backfiting he could be backfiting we could be backfiting you could be backfiting they could be backfiting
Perfect
I could have backfit, backfitted you could have backfit, backfitted he could have backfit, backfitted we could have backfit, backfitted you could have backfit, backfitted they could have backfit, backfitted
V-ing perfect
I could have been backfiting you could have been backfiting he could have been backfiting we could have been backfiting you could have been backfiting they could have been backfiting
Negation
Simple form
I couldn't backfit you couldn't backfit he couldn't backfit we couldn't backfit you couldn't backfit they couldn't backfit
V-ing form
I couldn't be backfiting you couldn't be backfiting he couldn't be backfiting we couldn't be backfiting you couldn't be backfiting they couldn't be backfiting
Perfect
I couldn't have backfit, backfitted you couldn't have backfit, backfitted he couldn't have backfit, backfitted we couldn't have backfit, backfitted you couldn't have backfit, backfitted they couldn't have backfit, backfitted
V-ing perfect
I couldn't have been backfiting you couldn't have been backfiting he couldn't have been backfiting we couldn't have been backfiting you couldn't have been backfiting they couldn't have been backfiting
Interrogative form
Simple form
could I backfit? could you backfit? could he backfit? could we backfit? could you backfit? could they backfit?
V-ing form
could I be backfiting? could you be backfiting? could he be backfiting? could we be backfiting? could you be backfiting? could they be backfiting?
Perfect
could I have backfit, backfitted? could you have backfit, backfitted? could he have backfit, backfitted? could we have backfit, backfitted? could you have backfit, backfitted? could they have backfit, backfitted?
V-ing perfect
could I have been backfiting? could you have been backfiting? could he have been backfiting? could we have been backfiting? could you have been backfiting? could they have been backfiting?
Interro-negative form
Simple form
couldn't I backfit? couldn't you backfit? couldn't he backfit? couldn't we backfit? couldn't you backfit? couldn't they backfit?
V-ing form
couldn't I be backfiting? couldn't you be backfiting? couldn't he be backfiting? couldn't we be backfiting? couldn't you be backfiting? couldn't they be backfiting?
Perfect
couldn't I have backfit, backfitted? couldn't you have backfit, backfitted? couldn't he have backfit, backfitted? couldn't we have backfit, backfitted? couldn't you have backfit, backfitted? couldn't they have backfit, backfitted?
V-ing perfect
couldn't I have been backfiting? couldn't you have been backfiting? couldn't he have been backfiting? couldn't we have been backfiting? couldn't you have been backfiting? couldn't they have been backfiting?