SN4 ""

No	Pattern	Freq
1	[verb] it [adv] for [adj] [noun]	64
2	[vb base] it [adv] for [adj] [noun]	18
3	[to-vb] it [adv] for [adj] [noun]	12
4	[vb past] it [adv] for [adj] [noun]	12
5	[v-ing] it [adv] for [adj] [noun]	9
6	[vb pp] it [adv] for [adj] [noun]	8
7	keep it [adv] for [adj] [noun]	7
8	it [be] [adv] for [adj] [noun]	84
9	it be [adv] for [adj] [noun]	84
10	it [is] [adv] for [adj] [noun]	43
11	it [was/were] [adv] for [adj] [noun]	41
12	it was [adv] for [adj] [noun]	37
13	it [verb] [adv] for [adj] [noun]	27
14	it is [adv] for [adj] [noun]	22
15	it 's [adv] for [adj] [noun]	21
16	it [vb past] [adv] for [adj] [noun]	14
17	it [vb -s] [adv] for [adj] [noun]	10
18	it [adv] [adv] for [adj] [noun]	8
19	it go [adv] for [adj] [noun]	7
20	it [adv] [adv] for [adj] [noun]	5
21	it went [adv] for [adj] [noun]	5
22	it [adv] [adj] for [adj] [noun]	49
23	it [adv] [adj] for [adj] [noun]	46
24	it [adv] difficult for [adj] [noun]	23
25	it [adv] difficult for [adj] [noun]	23
26	it [adv] [verb] for [adj] [noun]	18
27	it [adv] [be] for [adj] [noun]	14
28	it [adv] be for [adj] [noun]	14
29	it [adv] been for [adj] [noun]	12
30	it [adv] [been] for [adj] [noun]	12