SN4 ""

No	Pattern	Freq
1	[vb mod] [adv] have been [adj]	918
2	[modal v] [adv] have been [adj]	917
3	[modal v] not have been [adj]	520
4	[modal v] [not/n't] have been [adj]	520
5	would [adv] have been [adj]	460
6	would [adv] have been [adj]	452
7	[modal v] not have been [adj]	402
8	[modal v] [adv] have been [adj]	398
9	[modal v] [adv] have been able	159
10	may [adv] have been [adj]	152
11	may [adv] have been [adj]	152
12	[modal v] n't have been [adj]	118
13	might [adv] have been [adj]	91
14	might [adv] have been [adj]	91
15	[modal v] [adv] have been possible	84
16	could [adv] have been [adj]	82
17	could [adv] have been [adj]	82
18	[modal v] well have been [adj]	74
19	[modal v] well have been [adj]	74
20	can [adv] have been [adj]	56
21	can [adv] have been [adj]	45
22	[modal v] also have been [adj]	44
23	[modal v] also have been [adj]	44
24	[modal v] never have been [adj]	30
25	[modal v] never have been [adj]	30
26	must [adv] have been [adj]	29
27	must [adv] have been [adj]	29
28	[modal v] [adv] have been surprised	28
29	[modal v] [adv] have been easy	28
30	should [adv] have been [adj]	26