SN4 ""

No	Pattern	Freq
1	difficult [to-vb] the [adj] [noun]	175
2	difficult [to-vb] the [adj] [noun]	165
3	difficult [to-vb] the [adj] [noun sg]	121
4	difficult [to-vb] the [adj] [noun pl]	50
5	difficult [to-vb] the precise [noun]	11
6	difficult [to-vb] the precise [noun]	11
7	difficult to get the [adj] [noun]	9
8	difficult to assess the [adj] [noun]	7
9	difficult [to-vb] the [adj] effect	7
10	difficult [to-vb] the exact [noun]	6
11	difficult to see the [adj] [noun]	6
12	difficult [to-vb] the right [noun]	6
13	difficult to determine the [adj] [noun]	6
14	difficult [to-vb] the exact [noun]	6
15	difficult [to-vb] the right [noun]	6
16	difficult [to-vb] the real [noun]	5
17	difficult [to-vb] the [adj] effect	5
18	difficult to maintain the [adj] [noun]	5
19	difficult [to-vb] the real [noun]	5