There are many ways to determine the keyword completion, One of them is to use All in Title search operator with Google.
Then based on the number of Google search result you can know how difficult the keyword is .
This method is used by SEO professional for getting quick idea about the completion ( not in depth idea though ) .
Here are the steps :-
1- Go to Google and type allintitle: your keyword ( example allintitle: SEO Singapore)
2- Get the search result number and use the following table ( those numbers are the same used by seNuke software )
Google Search Result | Difficulty Level |
0-199 | Extremely easy! |
200-699 | Easy! |
700-1,499 | Doable |
1,500-2,999 | Not the easiest |
3,000-4,999 | Could be tough |
5,000-9,999 | Difficult |
10,000 or more | Don't Waste Your Time |