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