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