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