SN4 ""

No	Pattern	Freq
1	it is [adv] [adj] that a	114
2	it is [adv] [adj] that a	114
3	it is [adv] [verb] that a	68
4	it is [adv] [vb pp] that a	68
5	it is [adv] likely that a	25
6	it is [adv] likely that a	25
7	it is [adv] possible that a	15
8	it is [adv] possible that a	15
9	it is [adv] unlikely that a	14
10	it is [adv] unlikely that a	14
11	it is [adv] true that a	10
12	it is [adv] true that a	10
13	it is [adv] accept that a	7
14	it is [adv] clear that a	7
15	it is [adv] argue that a	7
16	it is [adv] surprising that a	7
17	it is [adv] surprising that a	7
18	it is [adv] accepted that a	7
19	it is [adv] clear that a	7
20	it is [adv] argued that a	7
21	it is [adv] assume that a	5
22	it is [adv] certain that a	5
23	it is [adv] establish that a	5
24	it is [adv] assumed that a	5
25	it is [adv] know that a	5
26	it is [adv] certain that a	5
27	it is [adv] known that a	5
28	it is [adv] established that a	5
29	it is [adv] [adv] that a	13
30	it is [not/n't] [adv] that a	11