trenera

In a sentence

• Spotkałem się wczoraj z moim trenerem fitness.

  I met with my fitness trainer yesterday.

  Here, 'trenerem' (the instrumental case of 'trener') refers to a person who is a fitness instructor, demonstrating its use to denote a title or role.

• Sukces drużyny zależy od umiejętności trenera.

  The team's success depends on the coach's skills.

  In this context, 'trenera' (genitive case of 'trener') indicates possession or relation, showing its use to describe the important attributes of the coach.

• Podziwiam determinację mojego trenera.

  I admire my coach's determination.

  Here, 'trenera' (accusative case of 'trener') is used to refer to a person in a direct action or feeling, illustrating its grammatical usage as the object of admiration.