Definite Object

The subject is connected to a word expressing an action, the gender of which can be a verb, participle, or noun.

For example:
Könyvet olvas (verb)
Könyvet olvasni (noun participle)
Könyvet olvasó (adjective participle)
Könyvet olvasva (adjective participle)
könyvet olvasás (noun)

The subject is the part of the sentence appearing as an extension of the predicate in the sentence, most often marked by the ending -t (e.g., almát, könyvet), but it can also be a noun participle, which We form verb+-ni (látni, kapni, etc.)

Its part of speech can be a noun, participle, or other noun used as a noun.

For example: Szeretek gitározni (noun participle); Éva almát evett (noun); Ilyet is hozz magaddal estére! (noun pronoun)

The subject can also be complex
For example: Szeretnék énekesnő lenni; Almát és körtét vettem a piacon.

In the case of an indefinite subject, the verb to which it is connected has a definite (subject) conjugation.
In this case, the subject can be preceded by a definite nominative, but not in all cases.

You can express the subject as a nominal pronoun (Szeretjük egymást; Szereti magát; Szereti őt; Szereti az enyémet.), or also a proper noun: Szeretem Lacit.