Keyword Analysis & Research: when does a prefix require a combining vowel

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
when does a prefix require a combining vowel	0.45	0.5	2008	94	44
when	0.97	0.8	7610	86	4
does	0.39	0.6	3093	71	4
a	0.18	0.2	8207	50	1
prefix	0.76	0.9	3555	3	6
require	1.7	0.6	7286	24	7
a	0.56	1	7422	28	1
combining	0.1	0.3	8056	2	9
vowel	1.68	0.5	132	15	5

Keyword	CPC	PCC	Volume	Score
when does a prefix require a combining vowel	1.44	0.3	9812	29