English verb conjugation
CAN SUSTAIN

Regular verb: sustain - sustained - sustained

Affirmation

Simple form	V-ing form
I can sustain you can sustain she can sustain we can sustain you can sustain they can sustain	I can be sustaining you can be sustaining she can be sustaining we can be sustaining you can be sustaining they can be sustaining
Perfect	V-ing perfect
I can have sustained you can have sustained she can have sustained we can have sustained you can have sustained they can have sustained	I can have been sustaining you can have been sustaining she can have been sustaining we can have been sustaining you can have been sustaining they can have been sustaining

Negation

Simple form	V-ing form
I can't sustain you can't sustain she can't sustain we can't sustain you can't sustain they can't sustain	I can't be sustaining you can't be sustaining she can't be sustaining we can't be sustaining you can't be sustaining they can't be sustaining
Perfect	V-ing perfect
I can't have sustained you can't have sustained she can't have sustained we can't have sustained you can't have sustained they can't have sustained	I can't have been sustaining you can't have been sustaining she can't have been sustaining we can't have been sustaining you can't have been sustaining they can't have been sustaining

Interrogative form

Simple form	V-ing form
can I sustain? can you sustain? can she sustain? can we sustain? can you sustain? can they sustain?	can I be sustaining? can you be sustaining? can she be sustaining? can we be sustaining? can you be sustaining? can they be sustaining?
Perfect	V-ing perfect
can I have sustained? can you have sustained? can she have sustained? can we have sustained? can you have sustained? can they have sustained?	can I have been sustaining? can you have been sustaining? can she have been sustaining? can we have been sustaining? can you have been sustaining? can they have been sustaining?

Interro-negative form

Simple form	V-ing form
can't I sustain? can't you sustain? can't she sustain? can't we sustain? can't you sustain? can't they sustain?	can't I be sustaining? can't you be sustaining? can't she be sustaining? can't we be sustaining? can't you be sustaining? can't they be sustaining?
Perfect	V-ing perfect
can't I have sustained? can't you have sustained? can't she have sustained? can't we have sustained? can't you have sustained? can't they have sustained?	can't I have been sustaining? can't you have been sustaining? can't she have been sustaining? can't we have been sustaining? can't you have been sustaining? can't they have been sustaining?