I could interfile you could interfile he could interfile we could interfile you could interfile they could interfile
V-ing form
I could be interfiling you could be interfiling he could be interfiling we could be interfiling you could be interfiling they could be interfiling
Perfect
I could have interfiled you could have interfiled he could have interfiled we could have interfiled you could have interfiled they could have interfiled
V-ing perfect
I could have been interfiling you could have been interfiling he could have been interfiling we could have been interfiling you could have been interfiling they could have been interfiling
Negation
Simple form
I could not interfile you could not interfile he could not interfile we could not interfile you could not interfile they could not interfile
V-ing form
I could not be interfiling you could not be interfiling he could not be interfiling we could not be interfiling you could not be interfiling they could not be interfiling
Perfect
I could not have interfiled you could not have interfiled he could not have interfiled we could not have interfiled you could not have interfiled they could not have interfiled
V-ing perfect
I could not have been interfiling you could not have been interfiling he could not have been interfiling we could not have been interfiling you could not have been interfiling they could not have been interfiling
Interrogative form
Simple form
could I interfile? could you interfile? could he interfile? could we interfile? could you interfile? could they interfile?
V-ing form
could I be interfiling? could you be interfiling? could he be interfiling? could we be interfiling? could you be interfiling? could they be interfiling?
Perfect
could I have interfiled? could you have interfiled? could he have interfiled? could we have interfiled? could you have interfiled? could they have interfiled?
V-ing perfect
could I have been interfiling? could you have been interfiling? could he have been interfiling? could we have been interfiling? could you have been interfiling? could they have been interfiling?
Interro-negative form
Simple form
could I not interfile? could you not interfile? could he not interfile? could we not interfile? could you not interfile? could they not interfile?
V-ing form
could I not be interfiling? could you not be interfiling? could he not be interfiling? could we not be interfiling? could you not be interfiling? could they not be interfiling?
Perfect
could I not have interfiled? could you not have interfiled? could he not have interfiled? could we not have interfiled? could you not have interfiled? could they not have interfiled?
V-ing perfect
could I not have been interfiling? could you not have been interfiling? could he not have been interfiling? could we not have been interfiling? could you not have been interfiling? could they not have been interfiling?