SN4 ""

No	Pattern	Freq
1	[conj] it [is] difficult for	48
2	that it [is] difficult for	18
3	that it [is] difficult for	18
4	[that] it [is] difficult for	18
5	[subord] it [is] difficult for	15
6	[coord] it [is] difficult for	15
7	and it [is] difficult for	11
8	and it [is] difficult for	11
9	[noun] it [is] difficult for	8
10	[noun sg] it [is] difficult for	7
11	[adv] it [is] difficult for	6
12	[verb] it [is] difficult for	6
13	[adv] it [is] difficult for	5
14	it [is] [adv] difficult for	117
15	it [is] [adv] difficult for	114
16	it [is] very difficult for	48
17	it [is] very difficult for	48
18	it [is] extremely difficult for	10
19	it [is] more difficult for	10
20	it [is] more difficult for	10
21	it [is] extremely difficult for	10
22	it [is] often difficult for	5
23	it [is] often difficult for	5
24	it [is] difficult [verb] for	13
25	it [is] difficult [to-vb] for	13
26	it [is] difficult to account for	6
27	it [is] difficult account for	6
28	it [is] difficult for [pron]	78
29	it [is] difficult for [pers pn]	67
30	it [is] difficult for [art]	33