SN4 ""

No	Pattern	Freq
1	have been [vb pp] for [adj] [noun pl]	92
2	have been [vb pp] for [adj] [noun sg]	80
3	have been [vb pp] for [adj] [noun]	76
4	have been [vb pp] for [det] [noun]	67
5	have been [vb pp] for [adj] year	31
6	have been [vb pp] for [adj] years	30
7	have been [vb pp] for [num] [noun]	25
8	have been [vb pp] for many [noun]	16
9	have been [vb pp] for some [noun]	16
10	have been [vb pp] for some [noun]	16
11	have been [vb pp] for many [noun]	16
12	have been [vb pp] for this [noun]	15
13	have been [vb pp] for this [noun]	15
14	have been used for [adj] [noun]	11
15	have been known for [adj] [noun]	10
16	have been [vb pp] for [adj] time	9
17	have been [vb pp] for [adj] time	9
18	have been developed for [adj] [noun]	9
19	have been [vb pp] for two [noun]	8
20	have been [vb pp] for two [noun]	8
21	have been [vb pp] for [num ord] [noun]	7
22	have been [vb pp] for [adj] reason	7
23	have been made for [adj] [noun]	6
24	have been [vb pp] for [adj] month	6
25	have been [vb pp] for [adj] purpose	6
26	have been [vb pp] for several [noun]	5
27	have been [vb pp] for [adj -er] [noun]	5
28	have been [vb pp] for several [noun]	5
29	have been [vb pp] for three [noun]	5
30	have been [vb pp] for three [noun]	5