SN4 ""

No	Pattern	Freq
1	[adv] twenty years ago	64
2	[adv] twenty years ago	58
3	[noun] twenty years ago	40
4	[noun sg] twenty years ago	33
5	[conj] twenty years ago	26
6	[verb] twenty years ago	22
7	[adj] twenty years ago	19
8	about twenty years ago	19
9	about twenty years ago	19
10	be twenty years ago	18
11	[be] twenty years ago	18
12	[subord] twenty years ago	15
13	[was/were] twenty years ago	15
14	[vb past] twenty years ago	14
15	than twenty years ago	13
16	over twenty years ago	13
17	over twenty years ago	13
18	than twenty years ago	13
19	[prep] twenty years ago	12
20	[prep] twenty years ago	12
21	[det] twenty years ago	12
22	[coord] twenty years ago	10
23	some twenty years ago	9
24	was twenty years ago	9
25	some twenty years ago	9
26	[adj] twenty years ago	7
27	were twenty years ago	6
28	almost twenty years ago	6
29	almost twenty years ago	6
30	even twenty years ago	5