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