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