Idioms on various languages
En un libro leí que en español cuando una muchacha rechaza un oferta de matrimonio dicen que ella da una calabaza. En nuestro país decimos que ella da una canasta.
Cómo se dice en ingles?
In a book I read in Spanish, when a girl rejects an offer of marriage they say: she gives a pumpkin. In our country we say that she gives a basket.
How do you say in English?
4 Answers
I would say the closest is "To turn someone ( or something) down" I can't think of anything that would specifically reference refusing a marriage proposal. It can be used in a few different contexts.
To reject a business proposal, offer, or terms "The customer turned down the salesman's offer." Another, "I received a call offering me the job, but I turned it down"
To indicate to adjust the intensity or level of something, "Please turn down [the volume of] the music." This can be used even if lowering the volume doesn't involve turning anything such as a knob. It can also be used more figuratively, "Stop jumping on the bed! Turn it [referring to the excitement level] down!"
To reject someone's intimate advances, regardless of context or gender. "John asked Jane out on a date, but she turned him down."
I am not aware of any similar expression in English that we say when a girl rejects an offer of marriage in in the UK!
Infact, I have never ever heard of any such saying in my 50 years of life. I suspect that we do not have any equivalent saying! 
Very interesting question, Porcu 
Oh, I understand now if it is that kind of expression you wanted, then I have certainly thought of one: "She gave him the brush off!"
This expresion is used to talk about a situation when a woman rejects a man's amorous advances when he shows an interest in her, It is more harsh than simply saying: she turned him down, the latter which can be done in a gentle respectful manner
I thought we didn't have such an expression because I thought you were meaning an expression only used with reference to being rejected as a possible suitor for marriage!
Many of the English expressions we use can be applied to a man's interest in a woman being rejected in relationships when he, for example wants to ask her out for a date. She turns him down!
If such a rejection occurs at the altar we would say: He jilted her/she jilted him at the altar
I hope this helps
There could be a myriad ways of saying it - but most are far to rude to be repeated here.
"She gave him the cold shoulder."
