SN4 ""

No	Pattern	Freq
1	[det] [vb mod] have been [adj]	173
2	[det] [modal v] have been [adj]	166
3	[det] would have been [adj]	92
4	[det] would have been [adj]	92
5	that [modal v] have been [adj]	82
6	this [modal v] have been [adj]	63
7	[det] may have been [adj]	30
8	[det] may have been [adj]	30
9	[det] must have been [adj]	16
10	[det] must have been [adj]	16
11	[det] [modal v] have been due	14
12	[det] could have been [adj]	13
13	[det] could have been [adj]	13
14	[det] might have been [adj]	11
15	these [modal v] have been [adj]	11
16	[det] might have been [adj]	11
17	[det] [modal v] have been true	10
18	[det] [modal v] 've been [adj]	7
19	[det] should have been [adj]	6
20	[det] [modal v] have been difficult	6
21	[det] should have been [adj]	6
22	[det] [modal v] have been awful	6
23	[det] [modal v] have been impossible	5
24	[det] [modal v] have been good	5
25	all [modal v] have been [adj]	5