Seven grammatical slots are represented by five written forms.
Form
Slot
Simple example
يَفْعَلَانِ
third-person masculine dual
هُمَا يَكْتُبَانِ
تَفْعَلَانِ
third-person feminine dual
هُمَا تَكْتُبَانِ
تَفْعَلَانِ
second-person masculine dual
أَنْتُمَا تَكْتُبَانِ
تَفْعَلَانِ
second-person feminine dual
أَنْتُمَا تَكْتُبَانِ
يَفْعَلُونَ
third-person masculine plural
هُمْ يَكْتُبُونَ
تَفْعَلُونَ
second-person masculine plural
أَنْتُمْ تَكْتُبُونَ
تَفْعَلِينَ
second-person feminine singular
أَنْتِ تَكْتُبِينَ
The dual second-person form is shared by masculine and feminine addressees. The feminine third-person dual and both second-person dual slots also share the written form تَفْعَلَانِ.