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