SN4 ""

No	Pattern	Freq
1	[pron] is [adv] difficult	783
2	[pers pn] is [adv] difficult	734
3	it is [adv] difficult	732
4	it is [adv] difficult	732
5	[noun] is [adv] difficult	385
6	[noun sg] is [adv] difficult	301
7	[adj] is [adv] difficult	72
8	[noun pl] is [adv] difficult	66
9	[det] is [adv] difficult	60
10	this is [adv] difficult	47
11	this is [adv] difficult	47
12	[Wh det] is [adv] difficult	42
13	[conj] is [adv] difficult	39
14	which is [adv] difficult	33
15	which is [adv] difficult	33
16	[coord] is [adv] difficult	22
17	[adv] is [adv] difficult	20
18	[verb] is [adv] difficult	17
19	that is [adv] difficult	16
20	[adv] is [adv] difficult	16
21	[that] is [adv] difficult	16
22	that is [adv] difficult	16
23	and is [adv] difficult	15
24	and is [adv] difficult	15
25	[noun prp] is [adv] difficult	11
26	[adj] is [adv] difficult	10
27	what is [adv] difficult	9
28	what is [adv] difficult	9
29	that is [adv] difficult	7
30	that is [adv] difficult	7