SN4 ""

No	Pattern	Freq
1	it have been [adj] [noun]	180
2	it have been [adj] [noun sg]	100
3	it have been [adj] [noun pl]	78
4	it have been [num] [noun]	71
5	it had been [adj] [noun]	71
6	it 's been [adj] [noun]	64
7	it have been [adj] [noun]	63
8	it have been [adj] year	46
9	it have been [adj] years	43
10	it has been [adj] [noun]	43
11	it have been [det] [noun]	42
12	it have been three [noun]	12
13	it have been three [noun]	12
14	it have been some [noun]	11
15	it have been some [noun]	11
16	it have been [adj] time	9
17	it have been [adj] month	9
18	it have been [adj] months	9
19	it have been this [noun]	9
20	it have been this [noun]	9
21	it have been [adj] way	7
22	it have been that [noun]	7
23	it have been [adj] time	7
24	it have been that [noun]	7
25	it have been five [noun]	7
26	it have been [adj] day	7
27	it have been five [noun]	7
28	it have been [adj] way	7
29	it have been hard [noun]	6
30	it have been [adj] practice	6