Certainty
How sure is the speaker that this is true?
المعنى
Certainty shows how sure the speaker is that a statement is true. The speaker can present something as certain, likely, or doubtful. Languages use words, verb forms, or tone of voice for this, and some have no special certainty form. How the speaker knows concerns the source of the information, not how strongly the speaker believes it.
طريقة التعرّف عليه
Look for what makes a statement sound certain, likely, or doubtful, rather than simply describing what happens.
في اللغة الأم
Arabic expresses confidence with optional words and phrases such as بالتأكيد, 'certainly,' and من المرجّح أنَّ, 'it is likely that.' Doubt can be stated explicitly with expressions such as لستُ متأكدًا, 'I am not sure.' An ordinary verb form does not require the speaker to mark a degree of certainty.
بالتأكيدِ، سنصلُ قبلَ الظهرِ. (Bi-al-taʾkīdi, sa-naṣilu qabla al-ẓuhr.)
من المرجَّحِ أنَّ المتجرَ مغلقٌ الآنَ. (Min al-murajjaḥi anna al-matjara mughlaqun al-ān.)
The statement is presented as likely, not certain.
لستُ متأكدًا من أنَّ هذا هو العنوانُ الصحيحُ. (Lastu mutaʾakkidan min anna hādhā huwa al-ʿunwānu al-ṣaḥīḥ.)
في اللغة قيد التعلم
English uses words such as definitely, probably, and maybe to show different levels of confidence. Must can express a strong conclusion, while may, might, and could express uncertainty about what is true. In this use, must does not give an order and may does not give permission.
The lights are on. Anna must be home.
Must expresses a strong conclusion, not a duty.
Ben might be on the bus.
The speaker presents this as possible, not certain.
They'll probably arrive before lunch.
Probably presents the arrival time as likely, but not certain.
Learners whose language separates words for rules from words for guesses may mistake must for an obligation or may for permission in these uses.