Vocabularies of babies under age two are slightly smaller when parents mix elements from two different languages in the same sentence, a new study from Concordia University found.

But growing up bilingual does not confuse a baby and make learning to speak more difficult, rather it gives them an edge, a growing body of research suggests. They may be slower in picking up each language than children raised speaking just one, but that temporary drawback is offset by the benefits of bilingualism, said Concordia University psychology professor Krista Byers-Heinlein.