If we understand what is being said when someone speaks to us our brain sends a signal that can be registered on an EEG. If instead we do not understand, or we simply are not paying attention, the listener’s brain does not send any signal. This discovery has many potential applications in many different fields. Children’s language progress can be monitored more precisely and we will be able to understand when they do not understand spoken language or are just beginning to do so. In turn this will allow us to decide when and what to teach with greater accuracy. Cases of dementia will be identified earlier and we will know if accident victims, who are unconscious, understand something/nothing/everything of what is being said. We will know if crucially important instructions in equally crucial jobs have been understood. Teachers will know if their lesson has been understood. We don’t yet know if the signal is also sent for written things that are understood or what happens when one thinks he/she has understood but actually has not, or maybe has only understood partially. We also don’t know the purpose of the signal. It is thought that maybe mum and dad are capable of capturing the signal sent by their child in response to what they say and consequently they have a measure of how they should be speaking to their children. Nature offers student and teacher a sophisticated means of communicating not based on failing tests or getting bad marks.