I have search service application configured.

Suppose my first name is "frankmartin" (no spaces)

When I search "frankmartin" then it displays search results in both "People" and "Site" search. But when I search "frank" it doesn't display any search result. Why is that?

**EDIT**

I am not using advanced search and have made this search results page using those search web parts which you can add in page to display results.