Traditionally, the grammatical sciences are divided into five branches:
Al-lugah (lexicon) concerned with collecting and explaining vocabulary
at-tasrīf (morphology) determining the form of the individual words
an-nahw (syntax) primarily concerned with inflection (iʿrab) which had already been lost in dialects.
al-ishtiqāq (derivation) examining the origin of the words
al-balāġah (rhetoric) which elucidates construct quality