• Go to Almaany and then to the Arabic-Arabic dictionary (see print screen).
• Or go directly to the Arabic-Arabic dictionary.
• Enter the word you want to look up the plural of, for example مِفْتَاحٌ and click 'ابحث' (search).

• Find the correct result and look for الجمع. The word مفتاح has two plural forms: مَفاتِيحُ, مَفَاتِيحُ



• If you enter the plural, you will get the explanation جمع مِفْتَاح, which means the plural of مِفْتَاحٌ. So pay close attention to the difference between الجمع (the plural) and جَمْعُ 'word in the singular' (the plural of 'word in the singular').