Recognizing Number from the Ending

Derived Nouns: The Active Participle (Ism Fa'il)

The endings make the number easy to recognize.

ExampleNumber
فَاعِلٌ / فَاعِلَةٌSingular
فَاعِلَانِ / فَاعِلَتَانِDual
فَاعِلُوْنَ / فَاعِلَاتٌPlural

So you can often identify the number by looking at the ending first.