Questions & Answers about Bardzo kocham mojego syna.
Why is it mojego syna instead of mój syn?
Syn is the direct object here, meaning it is the person receiving the action of the verb kocham (I love). Because a son is a living masculine noun (animate), it takes a special ending in this case. The dictionary form syn adds an -a to become syna, and the pronoun mój changes to mojego to match it.
Where is the word for "I" in this sentence?
You do not need to include it! The verb kocham ends in -m, which automatically tells us the subject is "I". You could say Ja bardzo kocham..., but Polish speakers usually drop the ja (I) unless they want to strongly emphasize who is doing the loving.
Why is bardzo (very much) at the beginning of the sentence instead of at the end like in English?
In Polish, adverbs like bardzo usually go right before the verb they describe. So instead of saying "I love very much" like in English, Polish naturally says bardzo kocham (literally: very much I love).
Would these endings be the same if I was talking about a non-living masculine object?
No, they would not. If you loved a non-living masculine thing, like a phone (telefon), the direct object form looks exactly like the basic dictionary form. You only use these special -ego and -a endings for masculine nouns that are alive, like people and animals.