In short

Arabic has two tenses, and you already know one of them. Lesson 14 gave you المُضارِع, the present, which marks the person with a prefix - أَكْتُبُ، تَكْتُبُ، يَكْتُبُ. The past, الماضي, does the opposite: the stem stays put and the person is bolted on at the end - كَتَبْتُ، كَتَبْتَ، كَتَبَ. Ten endings for the singular and plural, three more for the dual, and that is the entire tense. There is no “did”, no auxiliary, no irregular list to memorise.

Two things make this lesson worth slowing down for. First, the bare form كَتَبَ is not just “he wrote” - it is the shape every dictionary uses as its headword, so learning the past is learning how to look verbs up at all. Second, this is where the vowel marks stop being decoration. Written without them, كتبت is four different words: “I wrote”, “you wrote” (to a man), “you wrote” (to a woman) and “she wrote”. Only the تَشْكيل - or the surrounding sentence - tells them apart. Everything the path has said about vowelling collects its first real payment here.

The rule

1. The dictionary form is a finished sentence. Arabic has no infinitive. Where an English dictionary prints “to write”, an Arabic one prints كَتَبَ, which literally means “he wrote”. That form is the raw stem with nothing added, and it is the base you build all ten persons from. Three letters, three vowels: كَتَبَ. When this path or any dictionary names a verb, it names it in this shape.

2. الماضي is مَبْنِيٌّ - its ending never varies with the syntax. Nouns change their final vowel according to their job in the sentence (مَرْفوع، مَنْصوب، مَجْرور), and lesson 14’s present tense will later change its ending for mood. الماضي does neither. It is مَبْنِيٌّ, “built” - fixed. كَتَبَ ends in a fatḥa as subject-verb, after a question word, at the start of a sentence, in the middle of one, everywhere. That fatḥa is part of the word, not a case ending you may drop when speaking carefully:

• كَتَبَ الدَّرْسَ. - he wrote the lesson
• مَتى كَتَبَ الدَّرْسَ؟ - when did he write the lesson?

3. Consonant suffixes force a سُكون on the last radical. Six of the endings begin with a consonant - ـتُ، ـتَ، ـتِ، ـتُمْ، ـتُنَّ، ـنا - plus ـنَ for هُنَّ and ـتُما for the dual. Arabic does not tolerate the fatḥa of كَتَبَ sitting in front of them, so the third radical goes silent:

كَتَبَ + تُ -> كَتَبْتُ ، كَتَبَ + نا -> كَتَبْنا ، كَتَبَ + نَ -> كَتَبْنَ

Say it as a rhythm: the stem closes into one shut syllable, كَتَبْ, and the ending lands on top of it - كَتَبْتُ، كَتَبْنا، كَتَبْتُمْ. This single sukūn rule generates seven of the ten forms, and the dual كَتَبْتُما with them.

4. Vowel-initial suffixes leave the fatḥa alone. The other endings begin with a vowel, and there the last radical keeps its fatḥa: هِيَ كَتَبَتْ، هُما كَتَبا، هُما كَتَبَتا. The one to look at twice is هُمْ: the last radical rounds to a ḍamma and the و carries it as a long vowel - كَتَبوا. The ت of كَتَبَتْ is تاءُ التَّأْنيثِ السّاكِنَةُ, the feminine ت, and it carries no vowel of its own. (If the next word begins with الـ, that sukūn picks up a helping kasra so the two words can link: ذَهَبَتِ الطّالِبَةُ إِلَى المَدْرَسَةِ. You will hear it constantly; it changes nothing about the form itself.)

5. The silent alif in كَتَبوا. The ا at the end of كَتَبوا is not pronounced and not a vowel. It is a pure spelling device with a name - الأَلِفُ الفارِقَةُ, “the separating alif” - whose only job is to mark the و as واوُ الجَماعَةِ, the plural wāw, rather than a root letter or the word وَ (“and”). Whenever a verb ends in the plural wāw, that alif follows automatically: كَتَبوا، دَرَسوا، ذَهَبوا، جَلَسوا، فَهِموا. Never *كَتَبو. Treat وا as one indivisible two-letter ending and you will never drop it. (It does disappear once an object pronoun is attached to the verb - كَتَبوهُ - but object pronouns are lesson 29; until then, always write the alif.)

6. The ending already says who, so the pronoun is optional. كَتَبْتُ can only mean “I wrote”; no other person of the verb ends in ـْتُ. Adding أَنا is therefore not required, and sprinkling it over every sentence is one of the loudest marks of a beginner:

• ذَهَبْتُ إِلَى السّوقِ. - I went to the market (normal)
• أَنا ذَهَبْتُ إِلَى السّوقِ. - I went to the market (contrast: I did, not you)

The independent pronoun of lesson 6 goes in only when you want that emphasis, or when the sentence sets one person against another: أَنا دَرَسْتُ وهُوَ لَعِبَ. In plain narration, leave it out.

7. The middle vowel is the verb’s own property - only the dictionary knows it. In the dictionary form of an active Form I verb the first radical takes a fatḥa and the last one takes that fixed fatḥa. The middle radical is where verbs differ, and it gives three patterns:

Little in the meaning predicts which one you get - دَرَسَ and شَرِبَ are ordinary transitive verbs with different vowels. You cannot derive it, so you look it up and store it with the word. The good news is that it is stable: whatever vowel the middle radical has in كَتَبَ, it keeps in every one of the thirteen forms. شَرِبَ gives شَرِبْتُ، شَرِبَتْ، شَرِبْنا، شَرِبوا - the kasra never turns into a fatḥa. فَعُلَ is the rare one, and it is mostly qualities rather than actions (“became big”, “became good”).

8. Learn the past and present stems as one item. The past middle vowel does not predict the present one either: كَتَبَ gives يَكْتُبُ with a ḍamma, but جَلَسَ gives يَجْلِسُ with a kasra and ذَهَبَ gives يَذْهَبُ with a fatḥa. Dictionaries print both for exactly this reason. From now on, when you meet a new verb, write down the pair - كَتَبَ / يَكْتُبُ - never just one. Two tendencies help a little: فَعِلَ verbs mostly take a fatḥa in the present - شَرِبَ، سَمِعَ، فَهِمَ، لَعِبَ give يَشْرَبُ، يَسْمَعُ، يَفْهَمُ، يَلْعَبُ - and the rare فَعُلَ verbs always take a ḍamma (كَبُرَ / يَكْبُرُ).

9. كتبت: one skeleton, four words. Strip the vowel marks and كَتَبْتُ (I), كَتَبْتَ (you m.), كَتَبْتِ (you f.) and كَتَبَتْ (she) are all written كتبت. Real Arabic prints them that way. Two of them are especially treacherous because they differ only in where the sukūn sits:

• كَتَبْتَ - you wrote (to a man): sukūn on the ب, fatḥa on the ت
• كَتَبَتْ - she wrote: fatḥa on the ب, sukūn on the ت

The same two letters, the same two marks, swapped. In a real text the surrounding words settle it: a noun subject standing after the verb can only be third person - كتبت الطالبة رسالة is “the student wrote a letter” - and elsewhere it is who the paragraph is talking to, or about, that decides. That skill is the pronunciation guide’s business. Here, do the opposite: vocalize everything you write, out loud and on paper, until the two rhythms - كَتَبْتَ with its shut middle syllable against كَتَبَتْ with its open one - are two different sounds in your head rather than one ambiguous spelling.

10. What the tense actually means. الماضي reports an event as finished. It covers the English simple past (“I studied yesterday”), and very often the present perfect too (“I have already studied”), because Arabic does not split those apart. What it never does is describe an action in progress - “I was writing” is not الماضي on its own. String past verbs together and you have narration, which is what this tense is for:

دَخَلْتُ الغُرْفَةَ وجَلَسْتُ وفَتَحْتُ الكِتابَ. - I entered the room, sat down and opened the book.

Everything else about the past comes later: negating it with ما or لَمْ is lesson 37, “was/were” with كانَ is lesson 32, the sharpened “has just done” with قَدْ is lesson 45, and the passive كُتِبَ is lesson 52.

11. Sound verbs here, awkward roots later. Every verb in this lesson is الفِعْلُ الصَّحيحُ السّالِمُ - three solid consonants that never mutate. Verbs whose middle or last radical is و or ي reshape their stem in the past (قالَ، باعَ، مَشى) and are lessons 50 and 51; hamzated and doubled roots are lesson 49; the derived patterns like دَرَّسَ and اِسْتَقْبَلَ are lessons 46-48. None of that touches what you are learning now, because the thirteen endings in the table below are the same for every verb in the language. Only the stem in front of them changes - and with a weak root the stem and the ending can fuse (lessons 49-51).

Forms & patterns

Form I sound verb كَتَبَ (ك-ت-ب, “to write”) - the ten singular and plural persons:

The dual (lesson 12), three cells - no first-person dual exists:

The three middle-vowel classes, side by side in the cells that show the vowel best:

What to write in your vocabulary notebook - both stems, always:

One unvocalized skeleton, four readings - the reason this path prints the vowels:

Examples

Common mistakes

• كَتَبو -> كَتَبوا - the plural wāw always drags الأَلِفُ الفارِقَةُ behind it. Write وا as a single two-letter ending and the error cannot happen.
• كَتَبَتُ -> كَتَبْتُ - a consonant ending forces a sukūn on the last radical. There is no vowel between the ب and the ت.
• كَتَبَتْ رِسالَةً meaning “you wrote a letter” -> كَتَبْتَ رِسالَةً - كَتَبَتْ is “she wrote”. The two marks are simply swapped: sukūn on the ب for “you (m)”, sukūn on the ت for “she”.
• كَتَبْ -> كَتَبَ - the final fatḥa is the form itself, not a droppable case ending. (The vowelless ending you may have heard is a spoken-dialect habit, not الفُصْحى.)
• شَرَبْتُ -> شَرِبْتُ - the middle vowel belongs to the verb, not to the person. شَرِبَ is a فَعِلَ verb in every single cell.
• كَتَبْتُنَ -> كَتَبْتُنَّ - the ن of أَنْتُنَّ and هُنَّ is doubled; without the shadda the word does not exist.
• كَتَبْنا meaning “they (f) wrote” -> كَتَبْنَ - ـْنا is نَحْنُ, “we”. هُنَّ takes the bare ـْنَ with no alif.
• البَناتُ دَرَسوا -> البَناتُ دَرَسْنَ - a human feminine plural takes the feminine plural ending. The lesson-11 rule that lets you use a feminine singular applies to non-human plurals, not to girls.
• البِنْتانِ كَتَبا -> البِنْتانِ كَتَبَتا - the dual keeps its gender in the verb, even though the pronoun هُما does not.
• أَنا ذَهَبْتُ إِلَى السّوقِ وأَنا رَجَعْتُ بَعْدَ ساعَةٍ. -> ذَهَبْتُ إِلَى السّوقِ ورَجَعْتُ بَعْدَ ساعَةٍ. - the ending already carries “I”. Repeating أَنا turns plain narration into insistent contrast.

Tips

• Memorise the endings, not the verb. Chant ـْتُ، ـْتَ، ـْتِ، ـَ، ـَتْ، ـْنا، ـْتُمْ، ـْتُنَّ، ـوا، ـْنَ once and you can conjugate any verb in Arabic: the derived forms take exactly the same set, and weak roots take it onto a reshaped stem (lessons 49-51).
• Group the ten by shape: six start with a ت - the five “I / you” persons plus هِيَ’s ـَتْ - two start with a ن (نَحْنُ ـْنا and هُنَّ ـْنَ), and the two masculine third-person cells, كَتَبَ and كَتَبوا, carry neither. Three little families beat one flat list.
• Vocalize كتبت by hand every time you write it, at least for a week. This is the first place in the path where تَشْكيل earns its keep, and the habit is what makes reading real, unvowelled Arabic possible later.
• Every new verb enters your notebook as a pair, كَتَبَ / يَكْتُبُ. Recording only the past leaves you unable to say the present, and the vowel is genuinely unguessable.
• Narrate yesterday out loud in the first person: ذَهَبْتُ، دَرَسْتُ، شَرِبْتُ، عَمِلْتُ، رَجَعْتُ. Five verbs and a couple of time words already make a paragraph.
• Ignore for now: how to negate a past verb (lesson 37), how to say “was” (lesson 32), and anything with a و or ي inside the root (lessons 50-51). Sound verbs first.
• Do not hunt for a continuous past. “I was writing” needs a construction Arabic builds differently; الماضي on its own always reports a completed event.