SN4 ""

No	Pattern	Freq
1	[conj] it is difficult [prep]	67
2	[coord] it is difficult [prep]	26
3	that it is difficult [prep]	21
4	[that] it is difficult [prep]	21
5	that it is difficult [prep]	21
6	[subord] it is difficult [prep]	20
7	and it is difficult [prep]	17
8	and it is difficult [prep]	17
9	[noun] it is difficult [prep]	16
10	[noun sg] it is difficult [prep]	14
11	but it is difficult [prep]	9
12	but it is difficult [prep]	9
13	[adv] it is difficult [prep]	6
14	[verb] it is difficult [prep]	6
15	it is [adv] difficult [prep]	111
16	it is [adv] difficult [prep]	105
17	it is very difficult [prep]	31
18	it is very difficult [prep]	31
19	it is more difficult [prep]	12
20	it is more difficult [prep]	12
21	it is extremely difficult [prep]	11
22	it is extremely difficult [prep]	11
23	it is often difficult [prep]	9
24	it is often difficult [prep]	9
25	it is [not/n't] difficult [prep]	6
26	it is not difficult [prep]	6
27	it is sometimes difficult [prep]	6
28	it is sometimes difficult [prep]	6
29	it is not difficult [prep]	5
30	it is always difficult [prep]	5