SN4 ""

No	Pattern	Freq
1	[noun] and an	4767
2	[noun sg] and an	3202
3	[noun pl] and an	1164
4	[adj] and an	364
5	[noun prp] and an	314
6	[verb] and an	231
7	[adj] and an	202
8	[vb pp] and an	149
9	[num] and an	129
10	[adv] and an	88
11	[n mass] and an	71
12	[adv] and an	60
13	[pron] and an	47
14	[unc] and an	38
15	[pers pn] and an	35
16	[no cls] and an	34
17	[adv prt] and an	27
18	system and an	25
19	system and an	23
20	[det] and an	22
21	[v-ing] and an	20
22	[vb past] and an	20
23	[to-vb] and an	19
24	year and an	17
25	[prep] and an	17
26	man and an	17
27	[prep] and an	17
28	[letter] and an	16
29	group and an	15
30	it and an	15