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