SN4 ""

No	Pattern	Freq
1	[modal v] have been [prep]	1243
2	[vb mod] have been [prep]	1243
3	would have been [prep]	428
4	would have been [prep]	392
5	must have been [prep]	289
6	must have been [prep]	289
7	[adv] have been [prep]	258
8	[adv] have been [prep]	151
9	may have been [prep]	145
10	may have been [prep]	145
11	might have been [prep]	132
12	might have been [prep]	132
13	should have been [prep]	113
14	should have been [prep]	113
15	[not/n't] have been [prep]	107
16	not have been [prep]	107
17	could have been [prep]	99
18	could have been [prep]	99
19	not have been [prep]	69
20	n't have been [prep]	38
21	'd have been [prep]	36
22	will have been [prep]	36
23	will have been [prep]	33
24	well have been [prep]	28
25	well have been [prep]	28
26	never have been [prep]	20
27	never have been [prep]	20
28	[pron] have been [prep]	13
29	[pers pn] have been [prep]	13
30	[det] have been [prep]	11