SN4 ""

No	Pattern	Freq
1	[noun] at a time when the	102
2	[verb] at a time when the	73
3	[noun sg] at a time when the	65
4	[vb pp] at a time when the	31
5	[noun pl] at a time when the	29
6	[adj] at a time when the	25
7	[adv] at a time when the	24
8	[vb past] at a time when the	21
9	come at a time when the	20
10	[adv] at a time when the	17
11	[adj] at a time when the	15
12	be at a time when the	10
13	[be] at a time when the	10
14	came at a time when the	9
15	[vb -s] at a time when the	9
16	occur at a time when the	9
17	[conj] at a time when the	8
18	[v-ing] at a time when the	7
19	comes at a time when the	7
20	[noun prp] at a time when the	7
21	[adv prt] at a time when the	6
22	[num] at a time when the	6
23	was at a time when the	6
24	[was/were] at a time when the	6
25	place at a time when the	5
26	occurred at a time when the	5
27	at a time when the [noun]	252
28	at a time when the [noun sg]	192
29	at a time when the [adj]	100
30	at a time when the [adj]	93