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