SN4 ""

No	Pattern	Freq
1	[verb] to have been [vb pp] for	58
2	[vb pp] to have been [verb] for	26
3	seem to have been [verb] for	21
4	appear to have been [verb] for	13
5	[vb base] to have been [verb] for	12
6	[vb -s] to have been [verb] for	12
7	[vb past] to have been [verb] for	10
8	seem to have been [verb] for	10
9	[verb] to have been [v-ing] for	9
10	[verb] to have been used for	9
11	[verb] to have been use for	9
12	[vb infin] to have been [verb] for	7
13	say to have been [verb] for	6
14	seems to have been [verb] for	6
15	[verb] to have been design for	5
16	thought to have been [verb] for	5
17	said to have been [verb] for	5
18	[verb] to have been designed for	5
19	think to have been [verb] for	5
20	appears to have been [verb] for	5