SN4 ""

No	Pattern	Freq
1	[verb] that it was difficult	14
2	[vb past] that it was difficult	12
3	[adv] that it was difficult	12
4	[adv] that it was difficult	11
5	[noun] that it was difficult	11
6	so that it was difficult	8
7	[noun sg] that it was difficult	8
8	so that it was difficult	8
9	[adj] that it was difficult	7
10	[adj] that it was difficult	5
11	that it was [adv] difficult	24
12	that it was [adv] difficult	20
13	that it was very difficult	6
14	that it was very difficult	6
15	that it was difficult [to-vb]	41
16	that it was difficult [verb]	41
17	that it was difficult [prep]	8
18	that it was difficult [prep]	8
19	that it was difficult for	7
20	that it was difficult for	7