SN4 ""

No	Pattern	Freq
1	[verb] [Wh adv] it is that	46
2	explain [Wh adv] it is that	20
3	[to-vb] [Wh adv] it is that	18
4	[vb infin] [Wh adv] it is that	10
5	[vb base] [Wh adv] it is that	9
6	to explain [Wh adv] it is that	9
7	[prep] [Wh adv] it is that	8
8	[adv] [Wh adv] it is that	8
9	[prep] [Wh adv] it is that	8
10	[adv] [Wh adv] it is that	8
11	wonder [Wh adv] it is that	6
12	know [Wh adv] it is that	5
13	[Wh adv] [adj] it is that	33
14	[Wh adv] [adj] it is that	33
15	[Wh adv] it is [adj] that	43
16	[Wh adv] it is [adj] that	43
17	[Wh adv] it is [verb] that	40
18	[Wh adv] it is [vb pp] that	40
19	[Wh adv] it is important that	9
20	[Wh adv] it is important that	9
21	[Wh adv] it is clear that	7
22	[Wh adv] it is clear that	7
23	[Wh adv] it is assumed that	5
24	[Wh adv] it is essential that	5
25	[Wh adv] it is essential that	5
26	[Wh adv] it is assume that	5
27	[Wh adv] it is vital that	5
28	[Wh adv] it is vital that	5
29	[Wh adv] it is that [art]	29
30	[Wh adv] it is that [art]	29