Ability
Can someone do it?
المعنى
Ability tells us what someone can do, whether learned or not. It covers learned skills as well as what someone's body or mind allows them to do. Languages express it with helper verbs, endings, or ordinary phrases, and some have no special form for it. Unlike Permission, Ability concerns what someone can do, not what they are allowed to do.
طريقة التعرّف عليه
Check whether the message says someone has the skill or capacity to do something, rather than merely being allowed to do it.
في اللغة الأم
Arabic commonly expresses ability with يستطيع followed by أنْ and a verb naming the action. The following verb takes the subjunctive, often ending in -a instead of -u. يعرف كيف, meaning 'knows how,' can describe a learned skill.
أستطيعُ أنْ أسبحَ دونَ مساعدةٍ. (Astaṭīʿu an asbaḥa dūna musāʿada.)
يستطيع expresses ability, and the action follows أنْ.
أعرفُ كيفَ أستخدمُ هذا البرنامجَ. (Aʿrifu kayfa astakhdimu hādhā al-barnāmaj.)
After كيف, the verb keeps its ordinary present form.
في اللغة قيد التعلم
English commonly expresses ability with can followed by a verb without to. Could often describes general ability in the past, while was/were able to usually describes success on one occasion. Be able to also allows forms such as will be able to for future ability.
I can ride a bike.
Can expresses a skill, and ride follows without to.
When I was ten, I could swim across the pool.
Could describes an ability the speaker had at that age, not one particular swim.
The door was stuck, but we were able to open it.
Were able to shows that opening the door succeeded on this occasion.
Learners whose language marks the second verb in ability phrases may add to after can or could. Learners whose language uses one form for both general past ability and success on one occasion may overuse could.