أَمْسَكْتُ لِجَامًا — I held a bridle.
أَمْسَكْتُ: past-tense verb with subject pronoun.
لِجَامًا: direct object, accusative with fatḥa and tanwīn.
أَمْسَكْتُ بِلِجَامٍ — I held on to a bridle.
بِ: preposition. لِجَامٍ: genitive with kasra and tanwīn.
These are additional teaching examples, not printed sentences from the source.