Every keyword phrase will have multiple variations that should accompany it in the page. Such variations are plurals, singulars and stemmed variations such as “ing,” “ed,” etc. In many cases you can also swap word order. “pontiac used cars” can become “used pontiac cars.”
Don’t get locked into using the keyword phrase precisely as its most often searched, even if the stemmed variations show little search volume. When writing, use all variations as they would naturally be used within the context of what you have to say.
This post is part of a continuing series on the topic of:
Optimizing for Maximum Search Engine Performance
Sub-Topic: Research Your Targeted Keywords.