English verb conjugation
COULD DETERIORATE

Regular verb: deteriorate - deteriorated - deteriorated

Affirmation

Simple form	V-ing form
I could deteriorate you could deteriorate she could deteriorate we could deteriorate you could deteriorate they could deteriorate	I could be deteriorating you could be deteriorating she could be deteriorating we could be deteriorating you could be deteriorating they could be deteriorating
Perfect	V-ing perfect
I could have deteriorated you could have deteriorated she could have deteriorated we could have deteriorated you could have deteriorated they could have deteriorated	I could have been deteriorating you could have been deteriorating she could have been deteriorating we could have been deteriorating you could have been deteriorating they could have been deteriorating

Negation

Simple form	V-ing form
I couldn't deteriorate you couldn't deteriorate she couldn't deteriorate we couldn't deteriorate you couldn't deteriorate they couldn't deteriorate	I couldn't be deteriorating you couldn't be deteriorating she couldn't be deteriorating we couldn't be deteriorating you couldn't be deteriorating they couldn't be deteriorating
Perfect	V-ing perfect
I couldn't have deteriorated you couldn't have deteriorated she couldn't have deteriorated we couldn't have deteriorated you couldn't have deteriorated they couldn't have deteriorated	I couldn't have been deteriorating you couldn't have been deteriorating she couldn't have been deteriorating we couldn't have been deteriorating you couldn't have been deteriorating they couldn't have been deteriorating

Interrogative form

Simple form	V-ing form
could I deteriorate? could you deteriorate? could she deteriorate? could we deteriorate? could you deteriorate? could they deteriorate?	could I be deteriorating? could you be deteriorating? could she be deteriorating? could we be deteriorating? could you be deteriorating? could they be deteriorating?
Perfect	V-ing perfect
could I have deteriorated? could you have deteriorated? could she have deteriorated? could we have deteriorated? could you have deteriorated? could they have deteriorated?	could I have been deteriorating? could you have been deteriorating? could she have been deteriorating? could we have been deteriorating? could you have been deteriorating? could they have been deteriorating?

Interro-negative form

Simple form	V-ing form
couldn't I deteriorate? couldn't you deteriorate? couldn't she deteriorate? couldn't we deteriorate? couldn't you deteriorate? couldn't they deteriorate?	couldn't I be deteriorating? couldn't you be deteriorating? couldn't she be deteriorating? couldn't we be deteriorating? couldn't you be deteriorating? couldn't they be deteriorating?
Perfect	V-ing perfect
couldn't I have deteriorated? couldn't you have deteriorated? couldn't she have deteriorated? couldn't we have deteriorated? couldn't you have deteriorated? couldn't they have deteriorated?	couldn't I have been deteriorating? couldn't you have been deteriorating? couldn't she have been deteriorating? couldn't we have been deteriorating? couldn't you have been deteriorating? couldn't they have been deteriorating?