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