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