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