Arder means 'to burn' (to be on fire / be ablaze), and it is a regular -er verb. It differs from quemar ('to burn something'): arder describes the thing that is burning, while quemar is the action you do to it. La casa arde (the house is burning / ablaze), la sopa está ardiendo (the soup is boiling hot). It appears in vivid figurative phrases like arder de rabia ('to be burning with anger'). Because it adds intensity to description, arder is a useful higher-level verb. As a regular -er verb the conjugation is predictable.
Arder = to be burning; quemar = to burn something.
Very hot
Está ardiendo (it's boiling hot).
Figurative
Arder de rabia (to burn with anger).
Common phrases using arder
Fixed expressions worth knowing — they come up in listening, reading and writing tasks.
Idiomatic expressions
arder de rabiato burn with anger
estar que ardeto be tense / heated
Grammar notes
arder is a regular -er verb — it follows the standard -er pattern in every tense. That makes it a good one to drill: if you know arder, you know the template for all regular -er verbs.
Practice arder — free
Type conjugations from memory and get instant feedback. That's how you actually build the automatic recall the exam needs — not from reading tables.