The Particle に as an Object Marker and Indirect Object Marker
に as an object marker
As opposed to the object marker を, the object marker にis used with certain verbs to induce a sense of directionality. It is commonly used with verbs when they involve interaction with other people.
Ashita tomodachi ni aimasu.
(I am meeting my friend tomorrow.)
Watashi wa jitensha ni notta.
(I rode a bicycle.)
に as the indirect object marker
Wherein the particleを is used to mark the direct object of a clause, the particle に is used to mark the indirect object marker, or in other words, the recipient entity of a verb. In most cases, the に can be translated and interpreted as “to” but can also adopt such meanings as “from”.
Watashi wa kanojo ni tegami wo kaita.
(I wrote a letter to her.)
Tomodachi ni okane wo ageta.
(I gave my friend some money.)