لَّا تَسْمَعُ فِيهَا لَـٰغِيَةًۭ
Sentence structure
لَا negates تَسْمَعُ, whose understood subject is أَنْتَ. فِيهَا is linked to the verb and لَـٰغِيَةً is its object.
Ayah summary
No vain or hurtful speech will be heard there.
لَّا — Not
Grammar: A non-governing negative particle.
تَسْمَعُ — they will hear
Grammar: A second-person masculine-singular indicative imperfect with understood subject أَنْتَ.
فِيهَا — therein
Grammar: فِى is a preposition and attached هَا a third-person feminine-singular genitive pronoun. This phrase is linked to «تَسْمَعُ».
لَـٰغِيَةًۭ — vain talk
Grammar: An indefinite feminine-singular accusative object of تَسْمَعُ.