I can form you can form she can form we can form you can form they can form
V-ing form
I can be forming you can be forming she can be forming we can be forming you can be forming they can be forming
Perfect
I can have formed you can have formed she can have formed we can have formed you can have formed they can have formed
V-ing perfect
I can have been forming you can have been forming she can have been forming we can have been forming you can have been forming they can have been forming
Negation
Simple form
I can't form you can't form she can't form we can't form you can't form they can't form
V-ing form
I can't be forming you can't be forming she can't be forming we can't be forming you can't be forming they can't be forming
Perfect
I can't have formed you can't have formed she can't have formed we can't have formed you can't have formed they can't have formed
V-ing perfect
I can't have been forming you can't have been forming she can't have been forming we can't have been forming you can't have been forming they can't have been forming
Interrogative form
Simple form
can I form? can you form? can she form? can we form? can you form? can they form?
V-ing form
can I be forming? can you be forming? can she be forming? can we be forming? can you be forming? can they be forming?
Perfect
can I have formed? can you have formed? can she have formed? can we have formed? can you have formed? can they have formed?
V-ing perfect
can I have been forming? can you have been forming? can she have been forming? can we have been forming? can you have been forming? can they have been forming?
Interro-negative form
Simple form
can't I form? can't you form? can't she form? can't we form? can't you form? can't they form?
V-ing form
can't I be forming? can't you be forming? can't she be forming? can't we be forming? can't you be forming? can't they be forming?
Perfect
can't I have formed? can't you have formed? can't she have formed? can't we have formed? can't you have formed? can't they have formed?
V-ing perfect
can't I have been forming? can't you have been forming? can't she have been forming? can't we have been forming? can't you have been forming? can't they have been forming?