SN4 ""

No	Pattern	Freq
1	[conj] it have [been] the [adj]	28
2	[subord] it have [been] the [adj]	10
3	[coord] it have [been] the [adj]	10
4	that it have [been] the [adj]	8
5	[that] it have [been] the [adj]	8
6	that it have [been] the [adj]	8
7	but it have [been] the [adj]	7
8	but it have [been] the [adj]	7
9	if it have [been] the [adj]	5
10	if it have [been] the [adj]	5
11	it [vb mod] have [been] the [adj]	62
12	it [modal v] have [been] the [adj]	62
13	it would have [been] the [adj]	22
14	it would have [been] the [adj]	22
15	it must have [been] the [adj]	15
16	it must have [been] the [adj]	15
17	it may have [been] the [adj]	8
18	it could have [been] the [adj]	8
19	it could have [been] the [adj]	8
20	it may have [been] the [adj]	8
21	it should have [been] the [adj]	5
22	it should have [been] the [adj]	5
23	it have [adv] [been] the [adj]	25
24	it have [adv] [been] the [adj]	17
25	it have not [been] the [adj]	8
26	it have [not/n't] [been] the [adj]	8
27	it have always [been] the [adj]	6
28	it have always [been] the [adj]	6
29	it have not [been] the [adj]	5
30	it have [been] [prep] the [adj]	61