Communicating with babies before speech. As early as six months, your baby knows what he wants – and he’d tell you too if only he could talk – but he’s going to have to wait another six months or so before his vocal mechanism has developed enough to speak and a year or more before he can tackle more complex words.And a year’s an awfully long time when you’re a baby. No wonder he gets so frustrated – it’s enough to make you want to scream… That’s where sign language comes in. In Britain we use a variant called British Sign Language (BSL). It’s simple to learn a few signs to start with and then build up your repertoire as your baby progresses.