About twenty years ago various studies concluded that it is very important to speak to children because there is a close link between the number of words heard and language ability later in life. A new study conducted with instruments that examine brain development and that were not available 20 years ago says that it is not so useful to speak to children and instead it is very useful to have a conversation with kids. The back and forth of language in a conversation is a much more complex activity than simply listening. For a child to prepare an appropriate response to what someone has just said is a mental exercise that trains specific areas of the brain that are inactive if one is simply listening. The child gradually understands that replies and corresponding nuances change depending on whether we are speaking with a stranger, friend, relative or teacher. The child understands there are rules in a conversation. Single word replies are not suitable in most cases and the same goes for one thousand-word replies, long silences are probably inappropriate and there should be some connection between what was said and what we say. The child learns that speaking thoughtfully can be an extraordinary tool to reach objectives. New technologies now allow measurements of activity in the Broca center which is where language develops in the brain. Engaging in a conversation based on sounds and simple words strongly activates the Broca area. The more conversation in the early years of life and the more the Broca area develops and the better do language skills develop later in life as measured on standardized tests in adulthood.