Anabel, I have yet to have to write a query letter. The time is coming and I'm terrified.
If you got on an elevator with an agent or a publisher and you were invited to tell them about your story during the elevator ride, what would you say? You only have one or two floors to ride to get this guy or gal interested in your book. I'm saying keep it short. I am as anxious as you to read what the others say. There are places online where you can get tips and help in writing a query. Hopefully one of them will have a good one to recommend.
Get your query done. THEN translate it to English. THEN have a bilingual person help make sure your English and grammar are right on.
Good luck!

First, let me point you to a great resource:
http://jmeadows.livejournal.com/ -- you can add her to your friends list, although she doesn't usually friend back, she doesn't mind you friending her. She used to work as a slush reader for an agent and so knows how queries should work. She does this query project where you can submit your query to her and she'll critique it. But just read through the critiqued queries for a feel of what to do.
This is a poor attempt, mainly just correcting grammar. Queries should be written in present tense, not past. (I think!)
Muriel Blythe wants to escape everyone, [here I would name someone, instead of a generic "everyone" -- her brother? her family? her friends? her lover?] and to learn how to control her gift of seeing and conveying emotions.
She moves to Madrid to study psychology, but shadows attack her [for a reason unknown for her.---If she truly doesn't know why, then you might consider putting here what the attacks consist of, and cut the "for a reason unknown to her...". What does a shadow do? ]
Strange lights come to her aid. One in particular attracts her, a light between bright and dark.
Now she has to discover who are her attackers, who are her defenders, and why. {Something not easy when nobody wanted to reveal anything. -- This sentence is a fragment, so I'd re-word it somehow, maybe conveying more information, it's okay to be specific in a query, from what I read in jodi's blog} The discovery of a new gift will help her in her quest.
Amid all this mystery, Muriel discovers she has strong feelings for her defender--even though she knows nothing about him. She is torn between her rational mind and her feelings.
After a shocking revelation, she discovers nothing was as she thought, that in life she must be brave and never give up what she loves most.

It's a very good synopsis. It does need some cleaning up (mostly for verb tenses). Some of it can be cut back, and you need a few more specifics.
Suggestion:
Dear Agent/Editor:
[An opening line about why you want to work with this particular agent or editor / why they'd be perfect for this project.]
Glowing Shadow is my debut new-adult novel, a paranormal romance complete at 85,000 words.
Muriel Blythe moved to Madrid to study psychology. She needed to get away from everything and everyone to learn how to control her gift: the gift of seeing and conveying emotions. [I don't quite understand what the gift is--"seeing and conveying emotions"? All people do this. Can she read people's minds? Is this a supernatural gift?]
But in Madrid, mysterious shadows began to attack her, while strange lights helped her. Muriel struggled to discover what this eerie battle was all about, and why she had been drawn into the center of it. The discovery of a new gift helped her in her quest. [what new gift? Be specific.]
At the same time, Muriel developed strong feelings for her defender [How could she develop strong feelings if she knew nothing about the defender? Is the defender a person, or just one of the strange lights? What feelings is she developing--is this where the romance comes in? Tell us more about this love interest, if that is what it is.]
After a shocking revelation, [what shocking revelation? Be specific.] she discovered that nothing was as she thought, that in life you must be brave and never give up what you love most.

It's terrifying but we have to do it.
The idea of the elevator is a great way to see it. thank you!

thank you so much for the link and the help!
I will try to improve it with your recommendations!

Thank you so much for the help!! :)
I changed it to this:
Dear Agent/Editor:
[An opening line about why you want to work with this particular agent or editor / why they'd be perfect for this project.] ( I will leave this to complete it when I have the name of the agents)
Glowing Shadow is my debut new-adult novel, a paranormal romance complete at 85,000 words.
Muriel Blythe moved to Madrid to study psychology. She needed to get away from everything and everyone to learn how to control her gift: the supernatural gift of feeling what everyone felt around her and make them feel whatever she felt.
But in Madrid, mysterious shadows began to attack her, while strange lights helped her. Muriel struggled to discover what this eerie battle was all about, and why she had been drawn into the center of it. The discovery of being able to make astral trips helped her in her quest.
At the same time, Muriel developed strong feelings for her defender. One of the lights that in reality was a man. A man that make her feel love; something she never felt before. She loved him even when she didn’t knew who or what he really was but she was certain that he wasn’t totally a light, he was between light and shadow.
After founding why she had her supernatural gifts and that her love was forbidden, she also discovered that nothing was as she thought, that in life you must be brave and never give up what you love most.

Hi there,
I am just getting a moment to myself and saw your post a moment ago. I like the new version! I would suggest these changes:
* Second paragraph: I love the title. I would suggest changing "new adult" to "adult." "Debut" already tells us that it's new. However: I'm wondering if you mean that it is a "young adult" novel. Is Muriel 19, or 20? If so, I would say that it is a debut young adult novel.
Third paragraph: I would suggest the following treatment for the last words of the last sentence: "what everyone felt around her--and making them feel whatever she felt." You'd be adding a long hyphen, to emphasize "and making them feel whatever she felt," and changing "make" to "making."
Fourth paragraph: I would change this to present tense, to keep us in the moment. I would also add a couple of additional details, noted below:
But in Madrid, mysterious shadows begin to attack her, while strange lights help her (NOTE: How do they help her? A little more description here). Muriel struggles to discover what this eerie battle is all about, and why she has been drawn into the center of it. She learns she has the power to make astral trips (NOTE: astral trips into the past, into the future, or both?), and this helps her in her quest.
Fifth paragraph: Change this to present tense as well; I've also changed "that in reality" to "who in reality," because you're referring to a person:
At the same time, Muriel develops strong feelings for her defender: one of the lights who, in reality., is a man. A man who makes her feel love, something she has never felt before. Muriel began to love him even when she wasn't sure who or what he really was, but she was certain that he wasn’t totally a light--that he was something between light and shadow.
Suggest ending with this: Ultimately, Muriel discovers that nothing is as it once seemed--and that sometimes, you must be brave to keep from losing what you most love.
I hope this helps!! These are suggestions only; you'll know the right thing to do.
Take care, Jeni

Thank you so much for the suggestions Jeni.
Muriel is 19 and I thought if she was that age she entered the category new adult, I thought that the novel can't be young adult but I really prefer the category young adult!
Thank you so much I will make changes right now!:)

Oh and take care you too. have a wonderful day!