SN4 ""

No	Pattern	Freq
1	[modal v] not have been [prep]	67
2	[vb mod] not have been [prep]	67
3	would not have been [prep]	16
4	would not have been [prep]	16
5	may not have been [prep]	15
6	may not have been [prep]	15
7	could not have been [prep]	13
8	could not have been [prep]	13
9	should not have been [prep]	9
10	should not have been [prep]	9
11	will not have been [prep]	7
12	will not have been [prep]	7
13	not [verb] have been [prep]	6
14	not [vb infin] have been [prep]	5
15	not have been [verb] [prep]	276
16	not have been [vb pp] [prep]	265
17	not have been [adj] [prep]	144
18	not have been [adj] [prep]	127
19	not have been possible [prep]	30
20	not have been possible [prep]	30
21	not have been [adv] [prep]	14
22	not have been [noun] [prep]	14
23	not have been [v-ing] [prep]	11
24	not have been achieved [prep]	9
25	not have been [adv] [prep]	9
26	not have been achieve [prep]	9
27	not have been [noun sg] [prep]	9
28	not have been [adj -er] [prep]	8
29	not have been [det] [prep]	8
30	not have been aware [prep]	7