SN4 ""

No	Pattern	Freq
1	[noun] have [been] used for	82
2	[pron] have [been] used for	42
3	[noun sg] have [been] used for	38
4	[noun pl] have [been] used for	37
5	which have [been] used for	22
6	[Wh det] have [been] used for	22
7	which have [been] used for	22
8	[conj] have [been] used for	20
9	[pers pn] have [been] used for	19
10	[vb mod] have [been] used for	15
11	[modal v] have [been] used for	15
12	it have [been] used for	14
13	that have [been] used for	14
14	that have [been] used for	14
15	it have [been] used for	14
16	[that] have [been] used for	14
17	[verb] have [been] used for	9
18	[adv] have [been] used for	8
19	[adj] have [been] used for	8
20	[adv] have [been] used for	7
21	[vb pp] have [been] used for	6
22	could have [been] used for	6
23	could have [been] used for	6
24	[noun prp] have [been] used for	5
25	may have [been] used for	5
26	[coord] have [been] used for	5
27	may have [been] used for	5
28	have [adv] [been] used for	43
29	have [adv] [been] used for	27
30	have not [been] used for	16