SN4 ""

No	Pattern	Freq
1	it is [adv] [adj] for	1219
2	it is [adv] [adj] for	840
3	it is [not/n't] [adj] for	379
4	it is not [adj] for	379
5	it is not [adj] for	350
6	it is [adv] possible for	144
7	it is very [adj] for	110
8	it is very [adj] for	110
9	it is [adv] difficult for	78
10	it is [adv] important for	77
11	it is quite [adj] for	76
12	it is quite [adj] for	76
13	it is also [adj] for	69
14	it is also [adj] for	69
15	it is [adv] necessary for	66
16	it is [adv] easy for	61
17	it is [adv] unusual for	58
18	it is [adv] uncommon for	55
19	it is more [adj] for	52
20	it is more [adj] for	52
21	it is too [adj] for	42
22	it is too [adj] for	42
23	it is [adv] common for	41
24	it is [adv] impossible for	38
25	it is [adv] unknown for	37
26	it is particularly [adj] for	29
27	it is [adv] rare for	29
28	it is particularly [adj] for	29
29	it is n't [adj] for	29
30	it is therefore [adj] for	29