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