母は私の顔を見るなり腹を抱えて笑い出した。
- As soon as my mother saw my face she burst out laughing holding her sides.

母は私の顔を見るなり腹を抱えて笑い出した。 meaning: As soon as she looked at my face, my mother burst out laughing, holding her stomach.

⚫︎This grammar pattern is used to express that the next action happened immediately after the first action. ⚫︎It attaches to the dictionary form of a verb 見る. ⚫︎The subject is usually third-person, and it often expresses an unexpected or sudden action. ⚫︎In this sentence, 見るなり means as soon as [she] looked.

⚫︎This is a fixed idiomatic expression meaning to hold one's stomach from laughing so hard. ⚫︎It visually describes a state of uncontrollable laughter. ⚫︎In this sentence, it combines with the verb to show how the mother was laughing. ⚫︎It functions as an adverbial modifier in the sentence.

⚫︎This is an auxiliary verb attached to the stem of a continuous verb 笑い. ⚫︎It indicates the sudden beginning or onset of an action. ⚫︎笑う becomes 笑い出す, which means to start laughing suddenly or to burst out laughing. ⚫︎It highlights the abrupt change in the mother's behavior.

⚫︎The topic marker は attached to 母 indicates the subject or the topic of the sentence. ⚫︎The object marker を attached to 腹 and 顔 indicates the direct object of the actions 抱えて and 見る. ⚫︎These particles are fundamental for establishing the grammatical relationships between subjects, objects, and verbs. ⚫︎私の uses the possessive particle の to connect 私 and 顔.

⚫︎The sentence uses conjunctive forms 連用形 to connect clauses smoothly. ⚫︎見るなり connects the first clause to the main clause. ⚫︎抱えて uses the te-form of 抱える to show simultaneous actions or the manner of laughing. ⚫︎This chaining of verbs creates a natural and flowing narrative style typical of advanced Japanese.