I could summon you could summon she could summon we could summon you could summon they could summon
V-ing form
I could be summoning you could be summoning she could be summoning we could be summoning you could be summoning they could be summoning
Perfect
I could have summoned you could have summoned she could have summoned we could have summoned you could have summoned they could have summoned
V-ing perfect
I could have been summoning you could have been summoning she could have been summoning we could have been summoning you could have been summoning they could have been summoning
Negation
Simple form
I couldn't summon you couldn't summon she couldn't summon we couldn't summon you couldn't summon they couldn't summon
V-ing form
I couldn't be summoning you couldn't be summoning she couldn't be summoning we couldn't be summoning you couldn't be summoning they couldn't be summoning
Perfect
I couldn't have summoned you couldn't have summoned she couldn't have summoned we couldn't have summoned you couldn't have summoned they couldn't have summoned
V-ing perfect
I couldn't have been summoning you couldn't have been summoning she couldn't have been summoning we couldn't have been summoning you couldn't have been summoning they couldn't have been summoning
Interrogative form
Simple form
could I summon? could you summon? could she summon? could we summon? could you summon? could they summon?
V-ing form
could I be summoning? could you be summoning? could she be summoning? could we be summoning? could you be summoning? could they be summoning?
Perfect
could I have summoned? could you have summoned? could she have summoned? could we have summoned? could you have summoned? could they have summoned?
V-ing perfect
could I have been summoning? could you have been summoning? could she have been summoning? could we have been summoning? could you have been summoning? could they have been summoning?
Interro-negative form
Simple form
couldn't I summon? couldn't you summon? couldn't she summon? couldn't we summon? couldn't you summon? couldn't they summon?
V-ing form
couldn't I be summoning? couldn't you be summoning? couldn't she be summoning? couldn't we be summoning? couldn't you be summoning? couldn't they be summoning?
Perfect
couldn't I have summoned? couldn't you have summoned? couldn't she have summoned? couldn't we have summoned? couldn't you have summoned? couldn't they have summoned?
V-ing perfect
couldn't I have been summoning? couldn't you have been summoning? couldn't she have been summoning? couldn't we have been summoning? couldn't you have been summoning? couldn't they have been summoning?