*Quite often in Thai you don't need to say "I".
But, you can if you like. For men say "phom sabai dee". for women
say "di-chun sabai dee".
* For yes the reply is "dai" and for no the reply is "mai
dai"
I am single. (pom sot)
You are very beautiful. (koon suay mak)
You are very cute. (koon na-ruk mak)
Are you free tonight? (keun nee koon wang mai)
Do you have a boyfriend/girlfriend? (koon mee faen reu
yung)
I think I have fallen in love with you. (pom kit wa pom long
ruk koon)
Can I meet your parents? (pom bai pob por-mae koon dai
mai)
I want to marry you. (pom dtong gan dtang ngan gub
koon)
Can I kiss you? (joop dai mai)
Don't leave me. (ya ting pom)
I never lied to you. (pom mai ker-ee gor hok koon)
I will always be on your side. (pom yoo kang koon
sa-mer)
Take care of yourself. (do lae dtua eng duay na)
I want you to be happy. (pom dtong gan hai koon mee kwarm
sook)
Do you miss me? (koon kit teung pom mai)
I won't forget you. (pom ja mai leum koon)
You are my girlfriend. (koon ben fan pom)
You hurt me so much. (koon tam pom jep mak)
I will never cheat on you (pom ja mai nork jai
koon)
You are my sweetheart. (koon keu yot -ruk kong pom)
I will be faithful to you. (pom ja seu-sut dtor
koon)
I still remember the first moment we met. (pom yung jum
krang-raek tee row pob gun dai)
I miss you all the time. (pom kit-teung koon dta-lod
way-la)
Your romantic conversation portion a bit long 
