SN4 ""

No	Pattern	Freq
1	it is [adv] [vb pp] that [adj]	240
2	it is [adv] [verb] that [det]	141
3	it is [adv] [verb] that [adj]	94
4	it is [adv] [verb] that this	39
5	it is [adv] [verb] that this	39
6	it is generally [verb] that [adj]	36
7	it is [adv] know that [adj]	31
8	it is [adv] known that [adj]	31
9	it is well [verb] that [adj]	30
10	it is [adv] assume that [adj]	26
11	it is [adv] assumed that [adj]	26
12	it is often [verb] that [adj]	26
13	it is [adv] accept that [adj]	25
14	it is [adv] accepted that [adj]	25
15	it is widely [verb] that [adj]	23
16	it is also [verb] that [adj]	22
17	it is now [verb] that [adj]	21
18	it is sometimes [verb] that [adj]	18
19	it is [adv] said that [adj]	17
20	it is [adv] [verb] that such	17
21	it is [adv] [verb] that such	17
22	it is [adv] say that [adj]	17
23	it is [adv] [verb] that these	16
24	it is [adv] [verb] that these	16
25	it is [adv] recognise that [adj]	15
26	it is [adv] recognised that [adj]	15
27	it is [adv] [verb] that all	15
28	it is [adv] [verb] that all	15
29	it is [adv] [verb] that some	12
30	it is [adv] [verb] that [num]	12