Chavo or Chava, is the slang way to refer to an unknown young man or woman. It isnt disrespectful nor vulgar, its a very playful word that you can use in front of anyone. the same its the case for morro/huerco, but with small children, and the slang word for old people its ruco or ruca, but this one its a little stronger, and some might find it disrespectful to call and elder this way. Is mostly used by young people to speak about them when the older people isnt there. Some men also can call mi ruca or mi vieja (old lady) to their partner when they are with their friends.
El morro/huerco corre por el parque – The small child runs trough the park
Esa chava es muy bonita – That girl is really pretty
Mi ruca me abandono – Mi girl left me
Ese ruco siempre esta enojado – that old man is always angry.
Lately, people on the internet made a mix of chavo and ruco to refer to this adults that act like if they still are teenagers. They call them “chavorucos”, and while is kinda silly, is worth metioning because if you travel to Mexico, you may hear this.
I hope you have learned something new, about the spanish that real Mexicans talk on their everyday life.
If you want to improve your Spanish, I also give tutoring lessons on skype using this page that host many teachers from all over the world, and while I don’t really do grammar, I can help with conversation and doubts about the language. Also, if you are interested in any language besides spanish, there are teachers and tutors for any language there.