A category to which a word is assigned in accordance with its syntactic functions.
In English the main parts of speech are noun, pronoun, adjective, determiner, verb, adverb, preposition, conjunction, and interjection.

Parts of Speech

Noun	إسم	:	Name person, animal, thing, place, ideas, …
Pronoun	ضمير	:	Replace a noun.
Adjective	صفة	:	Describe or modify a noun or pronoun.
Verb	فعل	:	Indicate action or state of being or condition.
Adverb	ظرف حال	:	Describe a verb, adjective or another adverb.
Determiner	أداة	:	Limits or determines a noun.
Preposition	حرف جر	:	Link a noun, pronoun or noun phrase to some other part of the sentence.
Conjunction	حرف عطف	:	Join clauses, phrases, and words togethers for constructing sentences.
Interjection	حرف تعجب	:	Short exclamation.