Pragmatics is a field of linguistics that studies the ways in which context contributes to meaning. A sentence can have many meanings according to its context, and can be taken literally or not by the listener or reader.
The sentence “You have a green light” is ambiguous. Without knowing the context, the identity of the speaker, and his or her intent, it is difficult to infer the meaning with confidence. For example:
- It could mean that you have green ambient lighting.
- It could mean that you have a green light while driving your car.
- It could mean that you can go ahead with the project.
- It could mean that your body has a green glow.
- It could mean that you possess a light bulb that is tinted green.