SN4 ""

No	Pattern	Freq
1	[verb] been used for [det]	27
2	have been used for [det]	27
3	[vb -s] been used for [det]	11
4	has been used for [det]	10
5	[adv] been used for [det]	8
6	[vb base] been used for [det]	6
7	[vb past] been used for [det]	6
8	had been used for [det]	6
9	not been used for [det]	5
10	[not/n't] been used for [det]	5
11	have been used for [det]	5
12	been used [adv] for [det]	5
13	been used [adv] for [det]	5
14	been used for [det] [noun]	27
15	been used for [det] [noun pl]	15
16	been used for [det] years	13
17	been used for [det] year	13
18	been used for [det] [noun sg]	12
19	been used for [det] purpose	6
20	been used for [det] purpose	5