SN4 ""

No	Pattern	Freq
1	have been [vb pp] [prep] some	469
2	has been [vb pp] [prep] some	201
3	have been [vb pp] by some	145
4	have been [vb pp] in some	119
5	had been [vb pp] [prep] some	105
6	have been [vb pp] for some	101
7	have been [vb pp] [prep] some	86
8	have been [vb pp] [prep] some	41
9	have been [vb pp] to some	32
10	have been [vb pp] with some	28
11	have been [vb pp] at some	22
12	have been known [prep] some	21
13	to have been [vb pp] [prep] some	17
14	have been used [prep] some	15
15	have been found [prep] some	9
16	have been made [prep] some	7
17	's been [vb pp] [prep] some	7
18	have been recognised [prep] some	7
19	have been seen [prep] some	7
20	have been established [prep] some	7
21	have been described [prep] some	6
22	have been suggested [prep] some	6
23	have been argued [prep] some	5
24	have been adopted [prep] some	5
25	've been [vb pp] [prep] some	5
26	having been [vb pp] [prep] some	5
27	have been expressed [prep] some	5