This is a Part 2 of the last post, but this one is more of a clarifying post. This article is really worth reading, and may help to clear up some doubts or concerns.
As quoted on this blog... "It’s hard to know whether these errors are indicative of language impairment or the normal influence of one language on another. Let’s start by quoting our friend and colleague Kathryn Kohnert that bilingualism does not cause language impairment."
What a relief!! So... now go over and read the rest of the article.