I could learn you could learn she could learn we could learn you could learn they could learn
V-ing form
I could be learning you could be learning she could be learning we could be learning you could be learning they could be learning
Perfect
I could have learned, learnt you could have learned, learnt she could have learned, learnt we could have learned, learnt you could have learned, learnt they could have learned, learnt
V-ing perfect
I could have been learning you could have been learning she could have been learning we could have been learning you could have been learning they could have been learning
Negation
Simple form
I couldn't learn you couldn't learn she couldn't learn we couldn't learn you couldn't learn they couldn't learn
V-ing form
I couldn't be learning you couldn't be learning she couldn't be learning we couldn't be learning you couldn't be learning they couldn't be learning
Perfect
I couldn't have learned, learnt you couldn't have learned, learnt she couldn't have learned, learnt we couldn't have learned, learnt you couldn't have learned, learnt they couldn't have learned, learnt
V-ing perfect
I couldn't have been learning you couldn't have been learning she couldn't have been learning we couldn't have been learning you couldn't have been learning they couldn't have been learning
Interrogative form
Simple form
could I learn? could you learn? could she learn? could we learn? could you learn? could they learn?
V-ing form
could I be learning? could you be learning? could she be learning? could we be learning? could you be learning? could they be learning?
Perfect
could I have learned, learnt? could you have learned, learnt? could she have learned, learnt? could we have learned, learnt? could you have learned, learnt? could they have learned, learnt?
V-ing perfect
could I have been learning? could you have been learning? could she have been learning? could we have been learning? could you have been learning? could they have been learning?
Interro-negative form
Simple form
couldn't I learn? couldn't you learn? couldn't she learn? couldn't we learn? couldn't you learn? couldn't they learn?
V-ing form
couldn't I be learning? couldn't you be learning? couldn't she be learning? couldn't we be learning? couldn't you be learning? couldn't they be learning?
Perfect
couldn't I have learned, learnt? couldn't you have learned, learnt? couldn't she have learned, learnt? couldn't we have learned, learnt? couldn't you have learned, learnt? couldn't they have learned, learnt?
V-ing perfect
couldn't I have been learning? couldn't you have been learning? couldn't she have been learning? couldn't we have been learning? couldn't you have been learning? couldn't they have been learning?