When subconscious communicates it does not employ words. Its vocabulary is often visuals and themes that it uses to symbolize physic or physical events. Often this representation is fluid and highly contextual and must be interpreted within the cultural and situational framework of the dreamer.
However here are 7 most common themes in dreams that most people experience and their back of the envelope interpretations for a quick key :
Falling means having to rethink a choice that might not be working or charting a different direction from the one currently being pursued. Often it also symbolizes a need to let go and enjoy life more.
Flying on the other hand represents freedom and willingness to be. It often suggests your being free of social or behavioral restraints.
2) Appearing Naked/under-clothed in public:
It has nothing to do with physical nakedness but often points towards vulnerabilities and traits that make you appear exposed to others. It might also indicate that you feel fake and imperfect.
3) Being Chased/Out of breath
Often represents fears and anxieties that you want to escape from or events that you want to avoid. Being chased by animals might represent some passion or emotion, a mysterious figure or stranger might mean a trauma or repressed memory and by someone of opposite sex as a relationship or love situation.
Dying often represents an anxiety about the process of change or the fear of the unknown. Dream death of a loved one might mean that they are changing/growing up and you would have to deal with their movement.
Rebirth often indicates a new opening or new beginning and the excitement associated with that state.
5) Failing in test/Being Late
Tests are supposed to the natural state of waking life. So when you envision failing one or being late you are concerned about meeting challenges in your uptime. You feel under-confident or underprepared to take on life fully.
6) Falling teeth:
It might mean that you lost your appearance or your assertiveness to make an impact on the situation. In other words with a less than perfect mouth you might be concerned about your communication abilities or confidence in facing a demanding situation.
7) In a crash/accident/Pinned
It is often an indicator of loss of control or panic around being powerless to change a situation or a relationship.
So next time you have a dream which you remember, it is your innermost psyche communicating in an alien language. Use the key as above to prise open the meaning of what you are being told. It might take a little practice to decode the puzzle but is often worth the trouble.