In English, sweet words means words that are nice to hear and have a calm, friendly, happy, loving, affectionate meaning.
Sometimes, instead of using someone's name we will use words called terms of endearment.
Terms of endearment for people such as lovers, husbands, wives, family members or when talking to children.
Examples of terms of endearment:
Baby
Honey
Sweetheart
Sugar
Beautiful
Handsome
Princess
Angel
Love/My love

@Amir, I think you meant "See you later alligator" or "In a while crocodile". These sayings rely on rhyming the last two words.

@Leyla, I'm not clear what you are looking for. Do you mean sayings that are popular, sayings that sound nice, sayings used to say something is nice, or something else?

We literally use "sweet" to mean something is good, or even that someone is satisfied and calm. For example, "After we argued, we managed to have a proper discussion, and now we're both sweet."

"To be sweet on someone" means to treat that person kindly and affectionately. It usually means you and that person are not in a relationship, but you still treat him/her as someone special.

For softer expressions in place of harsh language, one of my favourites is "Strike a light!"  It's not so common these days. You might use it when you're shocked, surprised or frustrated. I think I like it because it's not a modification of stronger language, and by itself it's very innocent, but it still shows your feelings strongly.  

The girl in clip is like 'Leila Otadi', Iranian actor.

Thanks for song...

Richard

It is true I did not mean these words. Anyway thank you so much.