I could measure you could measure he could measure we could measure you could measure they could measure
V-ing form
I could be measuring you could be measuring he could be measuring we could be measuring you could be measuring they could be measuring
Perfect
I could have measured you could have measured he could have measured we could have measured you could have measured they could have measured
V-ing perfect
I could have been measuring you could have been measuring he could have been measuring we could have been measuring you could have been measuring they could have been measuring
Negation
Simple form
I could not measure you could not measure he could not measure we could not measure you could not measure they could not measure
V-ing form
I could not be measuring you could not be measuring he could not be measuring we could not be measuring you could not be measuring they could not be measuring
Perfect
I could not have measured you could not have measured he could not have measured we could not have measured you could not have measured they could not have measured
V-ing perfect
I could not have been measuring you could not have been measuring he could not have been measuring we could not have been measuring you could not have been measuring they could not have been measuring
Interrogative form
Simple form
could I measure? could you measure? could he measure? could we measure? could you measure? could they measure?
V-ing form
could I be measuring? could you be measuring? could he be measuring? could we be measuring? could you be measuring? could they be measuring?
Perfect
could I have measured? could you have measured? could he have measured? could we have measured? could you have measured? could they have measured?
V-ing perfect
could I have been measuring? could you have been measuring? could he have been measuring? could we have been measuring? could you have been measuring? could they have been measuring?
Interro-negative form
Simple form
could I not measure? could you not measure? could he not measure? could we not measure? could you not measure? could they not measure?
V-ing form
could I not be measuring? could you not be measuring? could he not be measuring? could we not be measuring? could you not be measuring? could they not be measuring?
Perfect
could I not have measured? could you not have measured? could he not have measured? could we not have measured? could you not have measured? could they not have measured?
V-ing perfect
could I not have been measuring? could you not have been measuring? could he not have been measuring? could we not have been measuring? could you not have been measuring? could they not have been measuring?