SN4 ""

No	Pattern	Freq
1	[verb] to have been	4218
2	[vb pp] have been	2025
3	seem have been	1441
4	[vb -s] have been	1370
5	seems have been	821
6	appear have been	802
7	[vb past] have been	734
8	[vb base] have been	707
9	[verb] has been	436
10	say have been	429
11	[verb] had been	416
12	appears have been	401
13	[vb infin] have been	379
14	seem have been	326
15	said have been	320
16	think have been	248
17	believe have been	242
18	[verb] have been	238
19	thought have been	217
20	report have been	205
21	reported have been	196
22	appear have been	183
23	believed have been	180
24	seem have been	150
25	seemed have been	143
26	know have been	137
27	have have been	128
28	[to-vb] have been	121
29	appeared have been	114
30	known have been	107