In linguistics, a grammar is the set of rules for how a natural language is structured, as demonstrated by its speakers or writers. Grammar rules may concern the use of clauses, phrases, and words. The term may also refer to the study of such rules, a subject that includes phonology, morphology, and syntax, together with phonetics, semantics, and pragmatics. There are, broadly speaking, two different ways to study grammar: traditional grammar and theoretical grammar.

இலக்கணம் என்பது மொழியின் அமைப்பையும், பயன்படுத்தும் விதத்தையும் வரையறை செய்யும் விதிகளைச் சுட்டுகிறது.