For a regular Form I present verb, the passive commonly has the pattern يُفْعَلُ: the prefix takes ḍamma and the penultimate radical fatḥa.
يَكْتُبُ → يُكْتَبُ (writes → is written); يَفْتَحُ → يُفْتَحُ (opens → is opened).
In يُكْتَبُ الدَّرْسُ, «الدَّرْسُ» is nominative nāʾib al-fāʿil.
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Mafʿūl Mā Lam Yusamma Fāʿiluhu — The Passive Subject
For a regular Form I present verb, the passive commonly has the pattern يُفْعَلُ: the prefix takes ḍamma and the penultimate radical fatḥa.
يَكْتُبُ → يُكْتَبُ (writes → is written); يَفْتَحُ → يُفْتَحُ (opens → is opened).
In يُكْتَبُ الدَّرْسُ, «الدَّرْسُ» is nominative nāʾib al-fāʿil.