Usually we understand it by name, otherwise you can ask or the person you're talking to mention it to you somewhere in sentence. don't worry, it's not a big deal :)

Do you mean, "how can I tell if 'o' means he, she or it?" By itself, you don't know. The "he/she/it" clue is given somewhere else. Maybe in the name (but Turkish, like English, has unisex names).

By analyzing what personal pronouns in the sentence used for (to the persons speaking, the persons spoken to, or the persons or things spoken about)

Welcome onboard :)

Hi! If you need help with spoken English, I'm glad to help you! I promise to go very slow and very patient! I am always looking for new friends all over the world! Please add me to QQ: 1990992857 or ooVoo: 6214337481 Thanks and take care! :) -- Jason