SN4 ""

No	Pattern	Freq
1	the [noun] it is [verb]	316
2	the [noun] it is [adj]	295
3	the [noun] it is [adj]	265
4	the [noun] it is [adv]	260
5	the [noun] it is [vb pp]	239
6	the [noun] it is [adv]	188
7	the [noun] it is [art]	98
8	the [noun] it is [art]	98
9	the [noun] it is [v-ing]	76
10	the [noun] it is [prep]	62
11	the [noun] it is [prep]	62
12	the [noun] it is a	56
13	the [noun] it is [not/n't]	54
14	the [noun] it is not	54
15	the [noun] it is not	49
16	the [noun] it is a	48
17	the [noun] it is the	38
18	the [noun] it is the	38
19	the [noun] it is possible	32
20	the [noun] it is possible	32
21	the [noun] it is important	27
22	the [noun] it is important	27
23	the [noun] it is [noun]	21
24	the [noun] it is necessary	19
25	the [noun] it is necessary	19
26	the [noun] it is now	17
27	the [noun] it is [conj]	17
28	the [noun] it is now	17
29	the [noun] it is difficult	16
30	the [noun] it is likely	16