Isn’t 18 mos too young to start a 2nd language?
Children are never to young to learn! The more a young child is exposed to a 2nd or even 3rd language, the more natural it comes to them. Think about how you learned your first language. Most likely your parents just repeated words while using motions, visual aids etc. At a young age, children quickly learn there is simply more than one way to say the same thing!