Hey everyone,

Is it ´hayırlı olsun´ that is used when someone enters a relationship? 

thanks

hayır means (aside from "no") good outcome. hayırlı olsun means "may this have a good outcome". it is used for almost everything. like "i bought a new car" "hayırlı olsun" or like "we have a new president" "hayırlı olsun" etc. so surely it can be used for a relationship as well.

by theology hayır means goodness without a return. for example you "do a hayır" it means you help someone but dont expect anything in return. so when applied to philosophy it would mean the goodness that Allah casts upon you but doesnt require you to make a sacrifice. this is "hayırlı" means its positive in every way, you wont spend any energy for it. its a treat from Allah to you.

  Basically, it is used for almost any positive new things in your life, other people may say this phrase to you to wish you goodness and good luck.

* For things you just bought. [ Not small things like patatos or domatos of course]

Ev almışsın hayırlı olsun. ---> I heard you bought a house, May it be good to you. [May that bring you goodness and health to you]

* It can be said to people who just got a new job.

Yeni işiniz hayırlı olsun ----> May your new job be good to you. [ Good luck with your new job, congratulations ]

* To someone who has just engaged, married or entered in  a new relationship.

Nişanlanmışsın hayırlı olsun. ---> I heard, you got engaged. Congrulations, may God bless your engagement.

* Say,your friend has just had hair transplanted , you  can say to him ;

Saç ektirmişsin hayırlı olsun. ---> You had had hair transplanted. May it bring you goodness. [ But ´n this specifc case be careful, try not to say it in public in this case, he may not want to hear this in public]

* Note that, if your friend has just recovered from his/her ilness, dont use this phrase, instead, we say " Geçmiş olsun ´´

* Say your friend opened a new business, you can use this phrase : 

Restoranın hayırlı olsun kardeş ---> May your new restaurant bring goodness to you. [may your business go good ]

* An unusal example for this phrase --->  if your friend has just quit smoking and you heard that, you may want to wish good luck to him/her.

Sigarayı bırakmışsın, hayırlı olsun. ---> I heard you quit smoking, good luck ! [May it bring good to you]

It will definetely bring good to the person if it lasts. I was really told this when tried to quit smoking , but it didnt work on me. I started  again a week later after I was told this wish. 

thankyou both for your explanations