Too much characters, second post :D !

"T'y" is very informal, but if you talk with friends or family it is a possible liaison you can do. We just gulp one of the vowel, you are right. 

You can use Y for many verbs that are not designating location.

- location : answer is " (verbe) où ?" (aller à Quelque Part, arriver à qp, etc.)

- something : answer is "(verbe) à quoi ?" (participer à Quelque CHose, jouer à qch, penser à qch, etc.)

But be careful about persons ! If the answer is "(verbe) à qui ?" we use "lui/leur" pronoms. BUT...some people don't, and use "y" 

"Je vais écrire à mon ami" -> à qui ? = à mon ami = lui "je vais lui écrire" 

But you might hear "je vais y écrire". I do that personally, but I think people do that because we want to speak faster or in a more comfortable way, so saying "lui" is too long, and can be shortened into a "i/y" sound. It  can also be because people, even natives makes mistakes, but I think it's more because of a "gulped" sound, a little bit like "I want to go" that becomes "I wanna"

"j'allais marcher à ma maison" sounds weird,

"j'allais rentrer chez moi"

"j'allais marcher jusqu'à chez moi"

is more natural :)

Do you have other questions :) ?

You will have two patterns 

1rst -> pattern where the verb is normally conjugated (present, imparfait, futur simple, conditionnel,...) 

"J'y vais"

"J'y allais"

"J'y irai"

"J'y irais"

= Y placed before the conjugated verb

Add negation :

"Je n'y vais pas"

"Je n'y allais pas"

"Je n'y irai pas"

"Je n'y irais pas"

= negation placed around Y and the conjugated verb

But also passé composé (which might sounds weird, I know...)

"J'y suis allé" (before the conjugated verb)

"Je n'y suis pas allé" (around the Y and conjugated verb) ("allé" is not exactly conjugated because it doesn't change depending on the subject you see ? "j'y suis allé" "t'y es allé" "nous y sommes allés". Ok, we add a S for the plurial, but it still doesn't count, plus you don't hear it, so it's not super super important ;) !)

2nd -> verbs that have a conjugated part, followed by an infinitive, like modal verbs, futur proche, and some other verbs.

"Je veux y aller"

"Tu dois y aller"

"Il aimerait y aller"

"Tu penses y aller ?"

= pronom is in between because we ask the question "aller où ?" and not "je veux où ?" "tu dois où ?" etc. so pronom sticks to the verb that answer the question "à (someplace/something)"

Add negation :

"Je ne veux pas y aller"

"Tu ne dois pas y aller"

"Il aimerait y aller"

"Tu ne penses pas y aller ?"

= negation doesn't care about the infinitive veb, it's like the negation sticks to the conjugated one (yup, negation is a little bit racist in my opinion) but pronom stays faithful to its verb :) and still stays before it.

It works for EVERY PRONOM :D and also you know what ? It also works for pronominal verbs, because "me" "te" "se" etc. ARE a kind of pronom ;) 

So technicallly I can use "y" to remplace all the places with: (A, Au, Aux et chez)

The metaphore was a little bit weird now that i think about it hahah. It'd better if you say "To dominate", somthing like to maitreser in french

Ok, you say "je suis rentré chez moi" but not "je suis rentré chez toi" (unless it's someone you are very close with, so you have this person's flat's key :D or you are a burglar XD ! ha ha !)

"Je suis rentré chez moi" => "j'y suis rentré" still sounds weird for me. Imagine a conversation : I'm on the phone with a friend "oui, je suis rentré chez moi là. Oui oui, je viens de rentrer, à l'instant." I'm not going to use Y for the second verb.

But, for a building yes I will. Imagine me, on the phone again "je viens d'arriver dans le centre commercial. Oui oui, j'y suis rentré, tu y es aussi ?" I'll use Y

And you are very right : foreign don't hear them, and this is also what makes them tricky to masterize (is this a word in English ? ha ha !)  for you guys. 

"So: The pronoun is racist toward the non-conjugated and they love the personal pronoun, when "y" got bored of the personal pronoun it had a coup de foudre with "ne" and they had a baby called "n'y" hahahah" I got confused with your explanation °___° I'm wondering if my explanation was clear now ha ha !

And yes, I am a teacher here :)

Merci Infiniment !^^

So it's possible to use "y" with chez also ?, Can i say? for example :

J'y suis rentre --> Vient de--> Je suis rentre chez "x" 

"x" ( moi, toi, lui, elle, eux.etc)

I just realized that maybe I made these mistakes because I didn't hear the "y" in the conversations that I have ( these were informal so I guess they didn't put effort in saying it and as you say, they gulped it !)

For example : J'y suis allé compare avec je dois y aller 

J'y suis allé semble plus dur je crois pour pouvoir identifier le "Y" compare avec je dois y aller.

So: The pronoun is racist toward the non-conjugated and they love the personal pronoun, when "y" got bored of the personal pronoun it had a coup de foudre with "ne" and they had a baby called "n'y" hahahah .

Thanks for your help!^^, Are you a teacher here? Honestly I'm new here so I'm looking for one.