SN4 ""

No	Pattern	Freq
1	has been [vb pp] for [noun pl]	99
2	have been [vb pp] for [noun pl]	66
3	had been [vb pp] for [noun pl]	61
4	have been [vb pp] for centuries	32
5	have been [vb pp] for years	28
6	have been used for [noun pl]	21
7	have been known for [noun pl]	15
8	have been made for [noun pl]	15
9	have been [vb pp] for [noun pl]	14
10	have been [vb pp] for months	9
11	's been [vb pp] for [noun pl]	9
12	have been [vb pp] for decades	7
13	have been given for [noun pl]	7
14	have been designed for [noun pl]	6
15	have been [vb pp] for weeks	5
16	have been [vb pp] for reasons	5
17	have been [vb pp] for generations	5