No, he won't take longer to learn to talk.

Raising bilingual children is sometimes believed to cause language delay, though evidence does not support this position.  Raising children bilingually neither increases nor reduces the chance of language disorder or delay.

I read this in this article on Multilingual Living today, an internet resource site for bilingual and multilingual families, and I couldn't help nodding in agreement.  For both my children, people would tell me that of course, my children would start talking later because they were being exposed to two languages (or in the case of the Bambino, THREE languages) simultaneously and it would take longer for them to absorb it all. 

This supposition is, in a fact, nothing more than a supposition.  It sounds logical but there is simply no evidence that supports this conclusion.  It certainly didn't hold true for my kids.  The Bambina was using around six to ten obvious words at 17 months (more, if you consider all those babytalk words that we might not understand) and was talking in complete sentences at age two years - well within the norm. 

The Bambino said mama at six months, papa (bahbah, in fact) at seven months, and now, at 13 months, says bah (ball), dide (outside) baba (baby) and some others.  In addition to mama, he says maman (French version) and mummy (anglo version).  The nanny says that he says some words in Malagasy as well (the nanny speaks Malagasy to the Bambino).  And to think that I know monolingual kids who started talking only at two or even three years of age!

The difference is that, while little monolingual Mikey might know 50 words in the one language he knows, Bilingual Beatrice will more likely know 25 words in each language.  She may seem like she's behind because you only recognize the words she says in your language, but in fact, she's not.