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