In short

English has one “they”, and it covers everyone and everything: the teachers are new, the books are new, they are new. Arabic asks a question English never asks. The moment a noun is plural, Arabic wants to know whether the plural stands for people or for anything else - things, animals, ideas, places, machines. People are called العاقِل and keep ordinary plural agreement. Everything else is غَيْرُ العاقِل, and Arabic treats its plural as a feminine singular: not “the books are new” but, quite literally, “the books is new” - الكُتُبُ جَديدَةٌ.

This is not a curiosity you can meet later. It reaches the adjective (الكُتُبُ الجَديدَةُ), the verb (وَصَلَتِ الرَّسائِلُ), the pronoun (أَيْنَ الكُتُبُ؟ - هِيَ عَلى المَكْتَبِ) and the demonstrative (هٰذِهِ الكُتُبُ). It is also the single rule learners break most often, because the English “they” keeps leaking in and produces *الكُتُبُ جُدُدٌ or *الكُتُبُ هُمْ. Fix one habit - when the plural is not people, think هِيَ - and a dozen different errors disappear at once.

The rule

1. Two classes of plural: العاقِل and غَيْرُ العاقِل. Arabic grammar sorts plural nouns by what they refer to, not by how they are spelled:

• العاقِل - human beings: مُعَلِّمونَ، طُلّابٌ، رِجالٌ، نِساءٌ، أَطْفالٌ، مُهَنْدِساتٌ.
• غَيْرُ العاقِل - everything else: كُتُبٌ، أَبْوابٌ، سَيّاراتٌ، مُدُنٌ، أَشْجارٌ، أَفْكارٌ، قِطَطٌ، كِلابٌ، لُغاتٌ، أَسْئِلَةٌ.

Note where animals fall. عاقِل means “possessing reason”, so it covers people only; cats, dogs, birds and horses are غَيْرُ العاقِل and follow the rule of things.

2. The rule itself, in one line. A plural of غَيْرِ العاقِل behaves, for every kind of agreement, exactly like a feminine singular noun. Whatever you would say about مَدْرَسَةٌ, you say about كُتُبٌ.

Compare a real feminine singular with a non-human plural and you will see they move together:

• المَدْرَسَةُ الجَديدَةُ - المَدارِسُ الجَديدَةُ
• المَدْرَسَةُ كَبيرَةٌ - المَدارِسُ كَبيرَةٌ
• المَدْرَسَةُ قَريبَةٌ، وَهِيَ جَميلَةٌ - المَدارِسُ قَريبَةٌ، وَهِيَ جَميلَةٌ

3. How the plural was formed makes no difference. Lessons 9 and 10 gave you two machines for building plurals. Neither one changes this rule:

• broken plural: الكُتُبُ الجَديدَةُ، الأَبْوابُ مَفْتوحَةٌ، المُدُنُ الكَبيرَةُ جَميلَةٌ
• sound feminine plural: السَّيّاراتُ كَبيرَةٌ، اللُّغاتُ الأَجْنَبِيَّةُ مُهِمَّةٌ

The ending ـات on السَّيّارات is very tempting: it looks like a feminine plural, so learners give it a feminine plural adjective, *السَّيّاراتُ كَبيراتٌ. Wrong. The shape of the noun decides nothing here; the referent decides everything, and cars are not people.

4. The gender of the singular makes no difference either. كِتابٌ is masculine, سَيّارَةٌ is feminine - once they are plural and non-human, both take the same feminine singular agreement: الكُتُبُ جَديدَةٌ، السَّيّاراتُ جَديدَةٌ. You can forget the singular’s gender at that point.

5. The adjective. Both jobs of the adjective from lesson 8 work as they always did; the adjective simply appears in its feminine singular form:

• attributive (inside the noun phrase, copying definiteness and case): الأَسْئِلَةُ الصَّعْبَةُ
• predicate (in a nominal sentence, indefinite and مَرْفوع): الأَسْئِلَةُ صَعْبَةٌ

Case and definiteness still behave normally, so the adjective changes its ending with the noun:

• مَرْفوع: الكُتُبُ الجَديدَةُ عَلى المَكْتَبِ.
• مَنْصوب: قَرَأْتُ الكُتُبَ الجَديدَةَ.
• مَجْرور: في الكُتُبِ الجَديدَةِ صُوَرٌ كَثيرَةٌ.
• indefinite: هٰذِهِ كُتُبٌ جَديدَةٌ.

6. The verb. A non-human plural subject takes a feminine singular verb - the same form you would use for هِيَ:

• past: وَصَلَتِ الرَّسائِلُ. / الرَّسائِلُ وَصَلَتْ.
• present: تَصِلُ الطّائِراتُ في الصَّباحِ. / الطّائِراتُ تَصِلُ في الصَّباحِ.

Do not write *الرَّسائِلُ وَصَلوا or *الطّائِراتُ يَصِلونَ. Those are the human forms. The order of verb and subject in a verbal sentence, and what agreement a human subject triggers when it follows its verb, are the subject of lesson 19; all you need now is that the feminine singular verb is right for non-human plurals in either order.

7. The pronoun. Refer back to a non-human plural with هِيَ, and attach ـها to nouns and particles:

• أَيْنَ الكُتُبُ؟ - هِيَ عَلى المَكْتَبِ.
• المُدُنُ القَديمَةُ جَميلَةٌ، وَشَوارِعُها ضَيِّقَةٌ.
• الحَقائِبُ ثَقيلَةٌ، لٰكِنَّها صَغيرَةٌ.

English “they” and “them” become هِيَ and ـها here, never هُمْ and ـهُمْ.

8. The demonstrative. “These books” is هٰذِهِ الكُتُبُ, exactly as you would say هٰذِهِ المَدْرَسَةُ. هٰؤُلاءِ is for people only. Take this as recognition for now - the demonstratives get their own lesson at step 13.

9. The human column, so the contrast is visible. People keep full plural agreement, and the adjective, verb and pronoun all match their gender:

• المُعَلِّمونَ الجُدُدُ وَصَلوا. هُمْ في الغُرْفَةِ. هٰؤُلاءِ المُعَلِّمونَ.
• المُعَلِّماتُ الجَديداتُ وَصَلْنَ. هُنَّ في الغُرْفَةِ. هٰؤُلاءِ المُعَلِّماتُ.

جُدُدٌ is the plural of جَديدٌ used for people; in modern Arabic it does not describe books. جَديداتٌ is the feminine plural used for people; it does not describe cars. Keep each word in its own column.

10. Nouns that name groups of people. Some non-human nouns have people inside them: الدُّوَلُ (states), الحُكوماتُ (governments), الشَّرِكاتُ (companies), الفِرَقُ (teams), الجامِعاتُ (universities). The noun names the entity, not the persons, so it follows the non-human rule: الشَّرِكاتُ الكَبيرَةُ، الفِرَقُ الرِّياضِيَّةُ جاهِزَةٌ، الدُّوَلُ العَرَبِيَّةُ.

11. Where the rule does not reach. It is a rule about plurals only. A singular non-human noun keeps ordinary agreement by its own gender - الكِتابُ الجَديدُ، البابُ مَفْتوحٌ - and the dual has a system of its own, which is the next lesson. Nothing here applies to الكِتابانِ.

12. Recognition only: the feminine plural is also attested. In poetry, older prose and some set expressions you will meet a non-human plural with a feminine plural adjective: الجِبالُ الشّامِخاتُ، اللَّيالي الطَّويلاتُ. It is not an error, and it is worth being able to read. But in modern writing the feminine singular is overwhelmingly the norm - الجِبالُ الشّاهِقَةُ - so produce that one and only that one. Treat the plural version the way you treat an old-fashioned English spelling: recognise it, do not imitate it.

Forms & patterns

The core contrast. Read it down the two columns, not across the rows:

The singular’s own gender is irrelevant once the noun goes plural:

The adjective still carries case and definiteness in the ordinary way:

Human plurals, for comparison only - both genders keep their own plural forms:

Left out here: the dual (lesson 12), the relative pronoun that agrees the same way (lesson 39), and the agreement of a verb that stands before a human subject (lesson 19).

Examples

Common mistakes

• الكُتُبُ جُدُدٌ. -> الكُتُبُ جَديدَةٌ. - جُدُدٌ is the human plural of جَديدٌ. Books are not people, so the adjective goes into the feminine singular.
• السَّيّاراتُ كَبيراتٌ. -> السَّيّاراتُ كَبيرَةٌ. - the ـات on the noun is a trap: the ending shows how the plural was built, not who it refers to. Cars still take كَبيرَةٌ.
• أَيْنَ الكُتُبُ؟ - هُمْ عَلى المَكْتَبِ. -> هِيَ عَلى المَكْتَبِ. - the English “they” leaking in. A non-human plural is referred to with هِيَ.
• هٰؤُلاءِ الكُتُبُ. -> هٰذِهِ الكُتُبُ. - هٰؤُلاءِ points at people only; things in the plural take the feminine singular هٰذِهِ.
• الرَّسائِلُ وَصَلوا. -> الرَّسائِلُ وَصَلَتْ. - وَصَلوا is “they (men) arrived”. A plural of things takes the same verb form as هِيَ.
• الطّائِراتُ يَصِلونَ في الصَّباحِ. -> الطّائِراتُ تَصِلُ في الصَّباحِ. - the present tense follows the same rule: تـ, not يـ … ـونَ.
• الأَبْوابُ مَفْتوحونَ. -> الأَبْوابُ مَفْتوحَةٌ. - the sound masculine plural ending belongs to people; doors get the feminine singular ة.
• الكِلابُ صِغارٌ. -> الكِلابُ صَغيرَةٌ. - animals are غَيْرُ العاقِل however alive they are, so صِغارٌ (a human plural) is out of place.
• المُعَلِّمونَ الجَديدَةُ. -> المُعَلِّمونَ الجُدُدُ. - the rule runs one way only. Do not put people into the feminine singular; they keep full plural agreement.
• الكِتابُ الجَديدَةُ. -> الكِتابُ الجَديدُ. - one book is not a plural. The feminine singular agreement is triggered by the plural, never by the singular noun.

Tips

• Before choosing any adjective, verb or pronoun, silently replace the plural with هِيَ. If الكُتُبُ = هِيَ, then هِيَ جَديدَةٌ، هِيَ وَصَلَتْ، هٰذِهِ - every choice follows.
• Run the two-question check: is the noun plural? are they people? Only “yes, yes” unlocks plural agreement; “yes, no” means feminine singular, every time.
• Learn the pair of adjectives together and keep them apart: جَديدَةٌ for things, جُدُدٌ for people. The same for صَغيرَةٌ / صِغارٌ and كَبيرَةٌ / كِبارٌ.
• A useful phrase to memorise as a whole: الكُتُبُ الجَديدَةُ against الطُّلّابُ الجُدُدُ. Say them back to back until the wrong one sounds wrong.
• Do not read the noun’s ending for the answer. سَيّاراتٌ ends in ـات and مُدُنٌ does not, yet both take exactly the same feminine singular agreement.
• When you read, use the rule backwards: a lone تـ verb or a feminine singular adjective with no feminine singular noun in sight usually means a plural of things is the subject.
• Ignore for now the literary feminine plural (الجِبالُ الشّامِخاتُ). Recognise it in a text and keep producing the feminine singular yourself.
• Leave the dual out of this entirely - it has its own agreement, and it is the next lesson.