For asking a question:
* என்ன (enna): This is the most common word for "what" in a question.
* எது (ethu): This is used when asking about a specific item or thing.
For describing something:
* என்ன (enna): This can also be used to describe something, like "What is this?"
For asking about a person's identity:
* யார் (yaar): This means "who" but can also be used to ask "what" when referring to a person's name or identity.
Examples:
* என்ன பண்றீங்க? (enna pannreeng?) What are you doing?
* எது உங்கக்கு பிடிச்சது? (ethu ungakku pidichchathu?) What do you like?
* என்ன இது? (enna ithu?) What is this?
* யார் இது? (yaar ithu?) Who is this?
Note: The specific usage of these words can vary depending on the context and the speaker's intention.