SN4 ""

No	Pattern	Freq
1	[verb] it difficult for	212
2	make it difficult for	209
3	[vb past] it difficult for	50
4	made it difficult for	49
5	[vb -s] it difficult for	41
6	makes it difficult for	40
7	making it difficult for	34
8	[v-ing] it difficult for	34
9	[vb infin] it difficult for	31
10	make it difficult for	30
11	[vb base] it difficult for	29
12	make it difficult for	29
13	made it difficult for	14
14	[vb pp] it difficult for	14
15	to make it difficult for	13
16	[to-vb] it difficult for	13
17	[be] it difficult for	5
18	be it difficult for	5
19	it be difficult for	228
20	it [be] difficult for	228
21	it [is] difficult for	169
22	it [adv] difficult for	165
23	it [adv] difficult for	165
24	it is difficult for	139
25	it more difficult for	69
26	it more difficult for	69
27	it [was/were] difficult for	55
28	it was difficult for	55
29	it very difficult for	52
30	it very difficult for	52