هذه الأعراض مهمة.

These symptoms are important.

Breakdown of هذه الأعراض مهمة.

• هذه: this
• مهم: important
• الأعراض: symptoms

Questions & Answers about هذه الأعراض مهمة.

Why is هذه used here instead of هذا?

Because الأعراض is a non-human plural noun, and in Modern Standard Arabic, non-human plurals usually take feminine singular agreement.

So even though الأعراض means symptoms and is plural, Arabic treats it grammatically like a feminine singular for agreement purposes in many cases.

That is why you get:

• هذه الأعراض = these symptoms
• not هذا الأعراض

This same pattern also affects the adjective later in the sentence.

Why is مهمة feminine singular if الأعراض is plural?

For the same reason: الأعراض is a non-human plural, and non-human plurals in MSA normally take feminine singular adjectives.

So:

• الأعراض مهمة = the symptoms are important

Even though the meaning is plural in English, the adjective is feminine singular in Arabic.

This is a very important rule:

• human plural nouns usually take true plural agreement
• non-human plural nouns usually take feminine singular agreement

So مهمة is exactly what you should expect here.

What is the singular of الأعراض?

The singular is عَرَض.

So: