I recently had coffee with my friend Jessica, who is finishing up her masters degrees in French and Teaching English as a Second Language and working on a thesis about young children's use of sign language. She's also been using French and sign language with her 18-month daughter, Madeleine, from birth. Here are two anecdotes she shared with me about Madeleine's language acquisition:
Jessica recently informed her daughter that it was time to prendre le bain. Madeleine replied by saying "Bath!" in English and doing the sign for bath. While at first Jessica was disappointed that Madeleine seemed to be choosing English over French, she thinks it's pretty neat that this toddler can translate among three languages.
Jessica's husband, Rich, has never formally studied French, but he's been picking up a lot just listening to his wife and baby daughter. The other day, the three of them were walking down some stairs with Jessica carrying Madeleine. She wanted to get down and walk by herself, but her maman told her, "Il faut porter des chaussures pour marcher sur les escaliers!" Rich concurred, saying "Yes, you need to wear shoes if you're going to walk down the stairs." While he probably couldn't have produced the sentence in grammatical French himself, he understands the basics now and has learned lots of vocabulary along with his daughter. (I'm hoping this will happen with my husband too!)
In general, Jessica says that her daughter understands everything said to her in English or French, responding appropriately to questions and instructions, even though she does not speak much yet. Jessica also confessed that during this summer, it's been harder for her to keep speaking French with her daughter due to many trips disrupting their routine. She's enthusiastic, though, and is planning on continuing to speak French with Madeleine--and with Madeleine's baby brother or sister due to arrive early next year. (Félicitations!!!)