SN4 ""

No	Pattern	Freq
1	it [is] sometimes [adj] [to-vb]	112
2	it is sometimes [adj] [verb]	100
3	it [is] sometimes [adj] [verb]	100
4	it [is] sometimes difficult [verb]	24
5	it [is] sometimes difficult [verb]	24
6	it [is] sometimes possible [verb]	21
7	it [is] sometimes possible [verb]	21
8	it [is] sometimes useful [verb]	14
9	it [is] sometimes useful [verb]	14
10	it 's sometimes [adj] [verb]	13
11	it [is] sometimes necessary [verb]	10
12	it [is] sometimes [adj -er] [verb]	10
13	it [is] sometimes hard [verb]	10
14	it [is] sometimes necessary [verb]	10
15	it [is] sometimes hard [verb]	10
16	it [is] sometimes easy [verb]	7
17	it [is] sometimes good [verb]	6
18	it [is] sometimes easier [verb]	5
19	it [is] sometimes [adj] use	5