SN4 ""

No	Pattern	Freq
1	[noun] [is] that [prep]	881
2	[noun sg] [is] that [prep]	741
3	[pron] [is] that [prep]	185
4	[verb] [is] that [prep]	145
5	[Wh det] [is] that [prep]	129
6	[adj] [is] that [prep]	125
7	[noun pl] [is] that [prep]	106
8	what [is] that [prep]	105
9	what [is] that [prep]	105
10	[adv] [is] that [prep]	84
11	[vb pp] [is] that [prep]	60
12	[adj] [is] that [prep]	46
13	[det] [is] that [prep]	45
14	[adv] [is] that [prep]	43
15	[Wh adv] [is] that [prep]	35
16	[noun prp] [is] that [prep]	30
17	problem [is] that [prep]	29
18	[conj] [is] that [prep]	27
19	[to-vb] [is] that [prep]	24
20	problem [is] that [prep]	24
21	which [is] that [prep]	23
22	[num ord] [is] that [prep]	23
23	[pers pn] [is] that [prep]	23
24	which [is] that [prep]	23
25	example [is] that [prep]	23
26	example [is] that [prep]	23
27	how [is] that [prep]	22
28	how [is] that [prep]	22
29	who [is] that [prep]	21
30	who [is] that [prep]	21