SN4 ""

No	Pattern	Freq
1	[noun] [subord] it is difficult	20
2	[adv] [subord] it is difficult	11
3	[noun sg] [subord] it is difficult	11
4	[adj] [subord] it is difficult	10
5	[adv] [subord] it is difficult	10
6	[adj] [subord] it is difficult	9
7	[noun pl] [subord] it is difficult	8
8	[coord] [subord] it is difficult	6
9	[conj] [subord] it is difficult	6
10	and [subord] it is difficult	5
11	and [subord] it is difficult	5
12	[subord] it is [adv] difficult	59
13	[subord] it is [adv] difficult	55
14	[subord] it is very difficult	12
15	[subord] it is very difficult	12
16	[subord] it is more difficult	11
17	[subord] it is more difficult	11
18	[subord] it is so difficult	6
19	[subord] it is often difficult	6
20	[subord] it is often difficult	6
21	[subord] it is so difficult	6
22	[subord] it is difficult [to-vb]	120
23	[subord] it is difficult [verb]	120
24	[subord] it is difficult [prep]	20
25	[subord] it is difficult [prep]	20
26	[subord] it is difficult to see	16
27	[subord] it is difficult see	16
28	[subord] it is difficult for	13
29	[subord] it is difficult for	13
30	[subord] it is difficult know	6