It depends on what the two words are.
There's no useful answer to this question as posed.
Trademarks are not all created equal. If we are talking about, say, the Yankee Candle Company, which is a major US retailer of candles, it's a good bet that Yankee Candle is going to be perceived by consumers as having some association with that company, since "Yankee Candle" is not a generic thing, even though it is a combination of two common words. "Coca" and "Cola" are two common words too. Put together, and they'll be happy to leave a smoking hole in the ground where you used to be.