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