To express strong probability, logical deduction, or absolute necessity ("must"), use the expression لا بد (literally "there is no escape"). Depending on what follows, it pairs with either أن or من.
Deductions with لا بد أن
When expressing that something must be true or must happen using a full clause (a subject and a verb, or a nominal sentence), use لا بد أن.
Because it uses the particle أن, any pronoun immediately following it must be attached as a suffix (e.g., أنها), and any noun immediately following it takes the accusative case.
For example, with an attached pronoun:
| The detective suspected the wife, so she must be the criminal. | اشتبه المحقق في الزوجة، لذا لا بد أنها هي المجرمة.ishtabaha al-muhaqqiqu fi az-zawjati, lidhâ lâ budda annahâ hiya al-mujrimatu. |
With a noun (المجرم) and a past-tense verb:
| Since there is no blood here, the murderer must have moved the corpse! | بما أنه ليس هناك دم هنا، لا بد أن المجرم نقل الجثة!bimâ annahu laysa hunâka damun hunâ, lâ budda anna al-mujrima naqala al-juthata! |
With a present-tense verb to state that an action must happen:
| She deduced that we must search the whole building. | استنتجت أنه لا بد أن نفتش كل المبنى.istantajat annahu lâ budda an nufattisha kulla al-mabnâ |
Necessity with لا بد من
To express that there is "no avoiding" something, use لا بد من followed directly by a noun or a verbal noun (مصدر). Because من is a preposition, the following noun takes the genitive case.
| The situation is dangerous; we need a quick solution to this mystery. | الموقف خطير؛ لا بد من حل سريع لهذا اللغز.al-mawqifu khatîrun; lâ budda min hallin sarîin lihâdhâ al-lughzi. |
Using a verbal noun (like البحث, "the search") is a common way to express a necessary action:
| The investigator deduced that this is a big conspiracy, so there is no avoiding the search for new evidence. | استنتج المحقق أن هذه مؤامرة كبيرة، لذا لا بد من البحث عن دليل جديد.istantaja al-muhaqqiqu anna hâdhihi mu'âmaratun kabîratun, lidhâ lâ budda mina al-bahthi 'an dalîlin jadîdin |
Detective Vocabulary in Action
Discussing an investigation requires specific terminology. Pay special attention to the prepositions paired with these key verbs:
- اشتبه في (to suspect)
- تورط في (to be involved in)
- استبعد (to rule out)
Let's see these verbs in action as we track down our suspects:
| We tracked the woman whom we suspected, and we found that she was involved in the crime. | تعقبنا المرأة التي اشتبهنا فيها، ووجدنا أنها تورطت في الجريمة.ta'aqqabna al-mar'ata allati ishtabahna fiha, wa wajadna annaha tawarratat fi al-jarima. |
| This must not be a suicide; we ruled out suicide after we found the corpse. | لا بد أن هذا ليس انتحارا؛ استبعدنا الانتحار بعدما وجدنا الجثة.lâ budda anna hâdhâ laysa intihâran; istab'adnâ al-intihâra ba'damâ wajadnâ al-juththah. |
Seeing the endings
This course writes Arabic the way books and newspapers print it, without the short-vowel marks, so the ending this lesson is about is usually something you hear in the audio but cannot see in the drills. Here are some of them with every vowel written out:
| as written | fully vocalized | meaning |
|---|---|---|
| بما أنه ليس هناك دم هنا، لا بد أن المجرم نقل الجثة! | بِمَا أَنَّهُ لَيْسَ هُنَاكَ دَمٌ هُنَا، لَا بُدَّ أَنَّ المُجْرِمَ نَقَلَ الجُثَّةَ! | Since there is no blood here, the murderer must have moved the corpse! |
| استنتجت أنه لا بد أن نفتش كل المبنى. | اِسْتَنْتَجَتْ أَنَّهُ لَا بُدَّ أَنْ نُفَتِّشَ كُلَّ المَبْنَى. | She deduced that we must search the whole building. |
| الموقف خطير؛ لا بد من حل سريع لهذا اللغز. | المَوْقِفُ خَطِيرٌ؛ لَا بُدَّ مِنْ حَلٍّ سَرِيعٍ لِهَذَا اللُّغْزِ. | The situation is dangerous; we need a quick solution to this mystery. |
Before a noun, the أن of لا بد أن has a shadda, and the noun after it is accusative: أَنَّ المُجْرِمَ. Before a verb it is أَنْ, with no shadda, and the verb is subjunctive, which on most forms is a final fatha: أَنْ نُفَتِّشَ. After لا بد من the noun is genitive, because من is a preposition: مِنْ حَلٍّ سَرِيعٍ. None of these marks is written, so you only hear the difference.
