I could field-test you could field-test he could field-test we could field-test you could field-test they could field-test
V-ing form
I could be field-testing you could be field-testing he could be field-testing we could be field-testing you could be field-testing they could be field-testing
Perfect
I could have field-tested you could have field-tested he could have field-tested we could have field-tested you could have field-tested they could have field-tested
V-ing perfect
I could have been field-testing you could have been field-testing he could have been field-testing we could have been field-testing you could have been field-testing they could have been field-testing
Negation
Simple form
I could not field-test you could not field-test he could not field-test we could not field-test you could not field-test they could not field-test
V-ing form
I could not be field-testing you could not be field-testing he could not be field-testing we could not be field-testing you could not be field-testing they could not be field-testing
Perfect
I could not have field-tested you could not have field-tested he could not have field-tested we could not have field-tested you could not have field-tested they could not have field-tested
V-ing perfect
I could not have been field-testing you could not have been field-testing he could not have been field-testing we could not have been field-testing you could not have been field-testing they could not have been field-testing
Interrogative form
Simple form
could I field-test? could you field-test? could he field-test? could we field-test? could you field-test? could they field-test?
V-ing form
could I be field-testing? could you be field-testing? could he be field-testing? could we be field-testing? could you be field-testing? could they be field-testing?
Perfect
could I have field-tested? could you have field-tested? could he have field-tested? could we have field-tested? could you have field-tested? could they have field-tested?
V-ing perfect
could I have been field-testing? could you have been field-testing? could he have been field-testing? could we have been field-testing? could you have been field-testing? could they have been field-testing?
Interro-negative form
Simple form
could I not field-test? could you not field-test? could he not field-test? could we not field-test? could you not field-test? could they not field-test?
V-ing form
could I not be field-testing? could you not be field-testing? could he not be field-testing? could we not be field-testing? could you not be field-testing? could they not be field-testing?
Perfect
could I not have field-tested? could you not have field-tested? could he not have field-tested? could we not have field-tested? could you not have field-tested? could they not have field-tested?
V-ing perfect
could I not have been field-testing? could you not have been field-testing? could he not have been field-testing? could we not have been field-testing? could you not have been field-testing? could they not have been field-testing?