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