The cardinal numbers from 13 to 19 are always found in the accusative case manṣūb (منصوب). Each of these numbers is formed from two separate words related through the compound dependency murakkab (مركب). The first word will be the first digit of the number and the second word will refer to the number 10. For example, nineteen would roughly read "nine and ten". The first word of the compound structure will have the opposite gender of the counted noun, while the second word will agree in gender with the counted noun.
Verse (74:30) below contains the number 19. Two words are used to form the number (nine and ten) and these are related through a compound dependency. Each of the two numeric words are in the accusative case manṣūb (منصوب). The first word is feminine and the second is masculine. In this verse the counted noun is omitted:
Fig 1. Compound number in verse (74:30).