SN4 ""

No	Pattern	Freq
1	[modal v] have been [noun prp]	179
2	[vb mod] have been [noun prp]	179
3	must have been [noun prp]	42
4	must have been [noun prp]	42
5	[adv] have been [noun prp]	41
6	could have been [noun prp]	38
7	could have been [noun prp]	38
8	[adv] have been [noun prp]	31
9	would have been [noun prp]	30
10	would have been [noun prp]	29
11	might have been [noun prp]	28
12	might have been [noun prp]	28
13	may have been [noun prp]	26
14	may have been [noun prp]	26
15	well have been [noun prp]	15
16	well have been [noun prp]	15
17	should have been [noun prp]	13
18	should have been [noun prp]	13
19	not have been [noun prp]	10
20	[not/n't] have been [noun prp]	10
21	it have been [noun prp]	7
22	[pron] have been [noun prp]	7
23	it have been [noun prp]	7
24	[pers pn] have been [noun prp]	7
25	n't have been [noun prp]	5
26	not have been [noun prp]	5
27	have been [prep] [noun prp]	81
28	have been [prep] [noun prp]	81
29	have been [noun] [noun prp]	56
30	have been [noun prp] [noun prp]	53