SN4 ""

No	Pattern	Freq
1	[vb mod] have been the [num ord]	76
2	[modal v] have been the [num ord]	76
3	[noun] have been the [num ord]	65
4	[pron] have been the [num ord]	45
5	would have been the [num ord]	32
6	would have been the [num ord]	31
7	[verb] have been the [num ord]	30
8	[pers pn] have been the [num ord]	29
9	[noun sg] have been the [num ord]	28
10	[noun prp] have been the [num ord]	24
11	must have been the [num ord]	16
12	must have been the [num ord]	16
13	[vb -s] have been the [num ord]	14
14	[noun pl] have been the [num ord]	13
15	[adv] have been the [num ord]	12
16	may have been the [num ord]	12
17	he have been the [num ord]	12
18	he have been the [num ord]	12
19	may have been the [num ord]	12
20	[vb pp] have been the [num ord]	11
21	[adj] have been the [num ord]	11
22	it have been the [num ord]	8
23	it have been the [num ord]	8
24	[det] have been the [num ord]	8
25	seem have been the [num ord]	8
26	seems have been the [num ord]	8
27	[Wh det] have been the [num ord]	7
28	who have been the [num ord]	6
29	[not/n't] have been the [num ord]	6
30	[adv] have been the [num ord]	6