SN4 ""

No	Pattern	Freq
1	it is often [adj] [verb]	214
2	it is often [adj] [to-vb]	212
3	it is often [adj] [verb]	189
4	it is often difficult [verb]	59
5	it is often difficult [verb]	59
6	it is often possible [verb]	39
7	it is often possible [verb]	39
8	it is often [adj -er] [verb]	23
9	it is often necessary [verb]	21
10	it is often necessary [verb]	21
11	it is often easy [verb]	15
12	it is often easier [verb]	13
13	it is often hard [verb]	11
14	it is often hard [verb]	11
15	it is often [adj] to use	10
16	it is often [adj] use	10
17	it is often useful [verb]	9
18	it is often useful [verb]	9
19	it is often impossible [verb]	8
20	it is often impossible [verb]	8
21	it is often good [verb]	7
22	it is often [adj] make	6
23	it is often [adj] to tell	6
24	it is often [adj] to make	6
25	it is often [adj] tell	6
26	it is often helpful [verb]	5
27	it is often preferable [verb]	5
28	it is often [adj] to determine	5
29	it is often better [verb]	5
30	it is often [adj] see	5