SN4 ""

No	Pattern	Freq
1	[verb] what it is [that]	38
2	[adv] what it is [that]	27
3	[prep] what it is [that]	24
4	[prep] what it is [that]	24
5	[adv] what it is [that]	21
6	[to-vb] what it is [that]	20
7	exactly what it is [that]	13
8	exactly what it is [that]	13
9	about what it is [that]	11
10	about what it is [that]	11
11	[noun] what it is [that]	11
12	[noun sg] what it is [that]	9
13	of what it is [that]	8
14	of what it is [that]	8
15	[conj] what it is [that]	7
16	[vb infin] what it is [that]	7
17	[coord] what it is [that]	7
18	out what it is [that]	6
19	and what it is [that]	6
20	out what it is [that]	6
21	[adv prt] what it is [that]	6
22	and what it is [that]	6
23	[pron] what it is [that]	5
24	know what it is [that]	5
25	[v-ing] what it is [that]	5
26	what [noun sg] it is [that]	5
27	what [noun] it is [that]	5
28	what it [vb -s] is [that]	16
29	what it [verb] is [that]	16
30	what it means is [that]	8