SN4 ""

No	Pattern	Freq
1	[prep] once the [noun]	117
2	[prep] once the [noun]	117
3	[conj] once the [noun]	116
4	[coord] once the [noun]	93
5	[verb] once the [noun]	89
6	be once the [noun]	78
7	[be] once the [noun]	78
8	at once the [noun]	77
9	at once the [noun]	77
10	[was/were] once the [noun]	74
11	but once the [noun]	61
12	but once the [noun]	61
13	was once the [noun]	56
14	[noun] once the [noun]	53
15	[adv] once the [noun]	51
16	[adv] once the [noun]	40
17	[vb pp] once the [noun]	37
18	for once the [noun]	36
19	for once the [noun]	36
20	[noun pl] once the [noun]	32
21	and once the [noun]	30
22	and once the [noun]	30
23	[subord] once the [noun]	21
24	were once the [noun]	18
25	[vb past] once the [noun]	15
26	[noun prp] once the [noun]	14
27	[pron] once the [noun]	13
28	[vb infin] once the [noun]	11
29	[pers pn] once the [noun]	8
30	[v-ing] once the [noun]	7