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