SN4 ""

No	Pattern	Freq
1	it is [adv] [vb pp] that [det]	133
2	it is [adv] [vb pp] that [adj]	93
3	it is generally [vb pp] that [adj]	36
4	it is [adv] [vb pp] that this	34
5	it is [adv] [vb pp] that this	34
6	it is [adv] known that [adj]	31
7	it is well [vb pp] that [adj]	30
8	it is often [vb pp] that [adj]	26
9	it is [adv] assumed that [adj]	26
10	it is [adv] accepted that [adj]	25
11	it is widely [vb pp] that [adj]	23
12	it is also [vb pp] that [adj]	21
13	it is now [vb pp] that [adj]	21
14	it is sometimes [vb pp] that [adj]	18
15	it is [adv] said that [adj]	17
16	it is [adv] [vb pp] that these	16
17	it is [adv] [vb pp] that such	16
18	it is [adv] [vb pp] that such	16
19	it is [adv] [vb pp] that these	16
20	it is [adv] [vb pp] that all	15
21	it is [adv] recognised that [adj]	15
22	it is [adv] [vb pp] that all	15
23	it is [adv] [vb pp] that [num]	12
24	it is [adv] [vb pp] that some	11
25	it is [adv] [vb pp] that some	11
26	it is [adv] [vb pp] that many	11
27	it is [adv] [vb pp] that many	11
28	it is [adv] argued that [adj]	10
29	it is commonly [vb pp] that [adj]	9
30	it is [adv] agreed that [adj]	9