what is the different between 'saranghae' 'saranghanda' 'saranghandago' and 'saranghaeyo' ?

what is 'i just want to be your friend' in Korean?

what is mean by 'naddo saranghae' ?

what is 'why you don't reply me? i just wanna be your friend' in Korean?

what is mean by '헐 아냐' ? my friend just say it to me and i don't know it..

what is the different between "Chan" and "Kun" ?

what is mean by 'chuoyo' ?