Questions & Answers about Мой сломанный телефон лежит на столе.
- Мой is a possessive pronoun meaning my.
- It must agree with the noun телефон in gender, number, and case.
Телефон is:
- masculine
- singular
- nominative (subject of the sentence)
So we choose:
- мой (masculine, singular, nominative), not моя (feminine) or моё (neuter).
Мне is a completely different form:
- мне = to me / for me (dative case of я)
- You use мне in sentences like Мне холодно (“I’m cold”, literally “It’s cold to me”) or Мне нужен телефон (“I need a phone”).
So мой телефон = my phone, while мне телефон on its own is ungrammatical here.
Сломанный is a past passive participle used like an adjective, from the verb сломать (“to break” in the sense of “to break something completely / to break once”).
Formation (for many verbs like this):
- infinitive: сломать
- take the past passive participle stem: сломан-
- add the long-form adjective ending for masculine nominative singular: -ный
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