SN4 ""

No	Pattern	Freq
1	[vb mod] have [been] [adj] for	241
2	[modal v] have been [adj] for	241
3	[modal v] have [been] [adj] for	241
4	[modal v] have [been] [adj] for	240
5	would have [been] [adj] for	126
6	would have [been] [adj] for	124
7	must have [been] [adj] for	47
8	must have [been] [adj] for	47
9	[modal v] have [been] responsible for	39
10	may have [been] [adj] for	28
11	may have [been] [adj] for	28
12	[modal v] have [been] difficult for	20
13	might have [been] [adj] for	20
14	might have [been] [adj] for	20
15	[modal v] have [been] easy for	15
16	[modal v] have [been] possible for	14
17	[modal v] have [been] impossible for	12
18	could have [been] [adj] for	10
19	could have [been] [adj] for	10
20	[modal v] have [been] good for	9
21	[modal v] have [been] necessary for	8
22	should have [been] [adj] for	7
23	[modal v] have [been] hard for	7
24	should have [been] [adj] for	7
25	[modal v] have [been] eligible for	6
26	[modal v] have [been] terrible for	5