18mo DS only has one word 'dada' and one sound 'woowoowoo' when he see's a dog. He makes other babbling sounds but nothing connected to any object/activity. He doesn't try to copy what we say. He has good understanding and can follow simple instructions. Would you have anything checked e.g. hearing; or should I just wait it out until he's 24months with crossed fingers? - should just say he is growing up in a bilingual environment if that makes any difference.