SN4 ""

No	Pattern	Freq
1	it is [adv] [adj] [verb] that	422
2	it is [adv] [adj] [to-vb] that	420
3	it is [adv] [adj] to say that	111
4	it is [adv] [adj] say that	111
5	it is also [adj] [verb] that	89
6	it is [adv] important [verb] that	69
7	it is [adv] true [verb] that	53
8	it is probably [adj] [verb] that	47
9	it is [adv] [adj] note that	40
10	it is [adv] [adj] to note that	39
11	it is [adv] fair [verb] that	39
12	it is very [adj] [verb] that	25
13	it is perhaps [adj] [verb] that	24
14	it is therefore [adj] [verb] that	23
15	it is [adv] [adj] to remember that	22
16	it is [adv] [adj] remember that	22
17	it is [adv] [adj] ensure that	21
18	it is [adv] [adj] to ensure that	21
19	it is [adv] [adj] assume that	21
20	it is [adv] [adj] to assume that	21
21	it is only [adj] [verb] that	21
22	it is [adv] interesting [verb] that	20
23	it is [adv] possible [verb] that	19
24	it is [adv] [adj] suggest that	16
25	it is [adv] [adj] to suggest that	16
26	it is [adv] reasonable [verb] that	15
27	it is equally [adj] [verb] that	14
28	it is quite [adj] [verb] that	14
29	it is [adv] difficult [verb] that	13
30	it is [adv] necessary [verb] that	12