1. As a verb meaning "to possess" or "to hold":
* Cael: This is the most common and versatile way to say "have".
* Example: "Mae gen i gar." (I have a car)
* Bod gyda: This literally means "to be with" and can be used to express possession.
* Example: "Mae llyfr gyda fi." (I have a book)
* Meddu: This is a more formal word meaning "to possess".
* Example: "Mae'r ty yn meddu ar ardd." (The house has a garden)
2. As part of a verb phrase:
* Cafodd: This is the past tense of "cael".
* Example: "Cafodd hi amser da." (She had a good time)
* Mae ganddi: This is the present tense of "cael" in the third person singular feminine.
* Example: "Mae ganddi gariad." (She has love)
3. In the context of having something done to you:
* Cael: This can be used to express having something done, like "having your hair cut".
* Example: "Rwy'n mynd i gael fy ngwallt wedi'i dorri." (I am going to have my hair cut)
The best way to choose the right word is to consider the specific context and the desired level of formality.