SN4 ""

No	Pattern	Freq
1	it is [prep] [det] [noun]	842
2	it is [prep] [det] [noun sg]	664
3	it is [prep] [det] [adj]	164
4	it is [prep] [det] [noun pl]	162
5	it is [prep] [det] [adj]	135
6	it is [prep] [det] reason	115
7	it is [prep] [det] reason	105
8	it is [prep] [det] point	59
9	it is [prep] [det] point	57
10	it is [prep] [det] sense	42
11	it is [prep] [det] sense	41
12	it is [prep] [det] [prep]	38
13	it is [prep] [det] [prep]	38
14	it is [prep] [det] [conj]	37
15	it is [prep] [det] context	37
16	it is [prep] [det] context	37
17	it is [prep] [det] [that]	32
18	it is [prep] [det] that	32
19	it is [prep] [det] that	32
20	it is [prep] [det] way	31
21	it is [prep] [det] [art]	30
22	it is [prep] [det] stage	30
23	it is [prep] [det] [art]	30
24	it is [prep] [det] stage	28
25	it is [prep] [det] background	26
26	it is [prep] [det] background	26
27	it is [prep] [det] area	23
28	it is [prep] [det] way	23
29	it is [prep] [det] time	22
30	it is [prep] [det] a	22