SN4 ""

No	Pattern	Freq
1	when [verb] to	644
2	when [vb pp] to	471
3	when [v-ing] to	170
4	when apply to	110
5	when applied to	107
6	when compared to	98
7	when compare to	98
8	when refer to	30
9	when speak to	29
10	when referring to	28
11	when add to	27
12	when added to	27
13	when expose to	25
14	when exposed to	25
15	when talking to	24
16	when talk to	24
17	when speaking to	17
18	when listen to	15
19	when subject to	13
20	when listening to	13
21	when subjected to	13
22	when spoken to	12
23	when put to	10
24	when write to	10
25	when link to	10
26	when put to	10
27	when writing to	10
28	when linked to	10
29	when going to	9
30	when return to	9