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