Certain groups of young men seem to be at high risk.
Don't ask a certain group of parents how they are doing this week.
Now certain groups seem to have gone cold on it.
Both are very popular for a certain group of people.
They want to fit in with friends or certain groups.
But some believe only certain groups are sitting down at the dinner table.
However, for certain groups in that population it is much more common.
"There's always going to be a certain group of people who want the real thing," he said.
You have to understand, you're dealing with a certain group of people.
In other cases, the laws address the problems of certain groups.