How to translate the Qur'an

In his 2011 book, Is That a Fish in Your Ear? - The Amazing Adventure of Translation, David Bellos, director of Princeton University's Program in Translation and Intercultural Communication, quotes St.Jerome "who translated the Bible into Latin and subsequently became the patron saint of translators", and who in a letter to his friend Pammichius, tried to counter criticisms of translations he had done so far:
Ego enim non solum fateor, sed libera voce profiteor me in interpretatione Graecorum absque sripturis sanctis ubi et verborum ordu mysterium est non verbum e verbo sed sensum exprimere de sensu
A translation of the above might read:
Thus I not only confess, but of my own free voice proclaim, that apart from translations of sacred scriptures from the Greek, where even the order of the words is a mysterium, I express not the word for the word, but the sense for the sense
Verbum e verbo can be considered synonymous with literal translation whilst sensum exprimere de sensu "to express the sense from the sense" equates to free translation. Jerome proclaims he doesn't do literal (word-for-word) translations except when translating sacred scriptures from the Greek (which is what he did, of course, most of the time!)
We might guess that Jerome feels uncomfortable giving a "free" translation when he feels the weight of the sacred on his shoulders. The mysterium of God's words, if you like, hinders him.

I wonder, do the translators of the Qur'an feel the same debilitating shadow of Allah falling across the page when they sit down to render the "actual words of God", as Muslims claim the Qur'an to be? How much of the Qur'an is simply "untranslatable", as some scholars and many Islamic apologists would have us believe?

Later in the same book, Bellos has a chapter entitled What Can't be Said Can't be Translated: The Axiom of Effability, whose main thrust can be summarised as follows:
One of the truths of translation - one of the truths that translation teaches - is that everything is effable.
By which he means that everything that is in a language can be translated into another language. Let us take the example used by Bellos to illustrate his point. A crew having returned from a space flight are holding a press conference. They have something spectacular to announce. They have encountered another civilisation and have learned the language of the extra-terrestrials.
"What did they have to say?" ask the excited journalists.
"We can't tell you that", reply the astronauts."Their language is entirely untranslatable"
It's not hard to imagine the response of the journalists, says Bellos.

So whilst we may freely admit that it's possible that the Qur'an's style is inimitable and impossible to render into a foreign language, the content or meaning cannot be ineffable just because it's in classical Arabic. Unless, that is, the original made no sense in places to start with.

To help us understand, let us return to Jerome's confession, but to an alternative translation of the Latin by a canon of Canterbury Cathedral:
For I myself not only admit but freely proclaim that in translating from the Greek (except in the case of the holy scripture where even the order of the words is a mystery) I render sense for sense, not word for word.
Bellos puts it in an even "slacker style" as he has it: I only translate word for word where the original - even the word order - is a complete mystery to me. What the canon is suggesting therefore is that Jerome sometimes can't understand a bloody word of what he's been asked to translate and on those occasions simply translates the words in isolation - much like a bad google translate.

Surely the actual words of God, as spoken by the Angel Gabriel to Muhammad and repeated by him and transcribed perfectly so that not a dot has changed in over 1, 400 years, don't provide equal difficulties for translators though...? And if they do, how have translators coped. Have they gone down the Jerome route and simply translated what they read, despite the fact it makes no sense?

In the case of the utterly confusing changes in pronoun which quranic "scholars" have had to invent a whole new stylistic terminology for  (ilifat) so as to justify it,, it seems the answer is yes

6:99. It is HE who sends down water from the sky, and with it WE bring forth vegetation of all kinds…
And it's the same for the infamous verse which appears to prohibit believers from being dutiful to their parents and not killing their children:
6: 151. Say: "Come, I will recite what your Lord has prohibited you from: Join not anything in worship with Him; be good and dutiful to your parents; kill not your children because of poverty - We provide sustenance for you and for them; come not near to Al-Fawâhish whether committed openly or secretly, and kill not anyone whom Allâh has forbidden, except for a just cause….
And when the Arabic seems to suggest Muhammad has slaves (instead of God)!
39: 53. Say: 'O my slaves who have transgressed against themselves despair not of the Mercy of Allâh…'
But sometimes the original Arabic is so nonsensical that some translators have abandoned Jerome's tactic and felt obliged to help Allah out...Here's 35:8 without any help
Is he, to whom the evil of his deeds made fairseeming, so that he considers it as good? Therefore, Allâh sends astray whom He wills, and guides whom He wills. So destroy not yourself in sorrow for them…. 
And here's the same verse with "helpful" additions in brackets by Assad, Yusuf Ali and Picktall
 Is, then, he to whom the evil of his own doings is [so] alluring that [in the end] he regards it as good [anything but a follower of Satan]? For, verily, God lets go astray him that wills [to go astray], and guides whom he will...
 Is he, then, to whom the evil of his conduct is made alluring, so that he looks upon it as good, (equal to one who is rightly guided)? For Allah leaves to stray whom He wills, and guides whom He wills.  
Is he, the evil of whose deeds is made fair seeming unto him so that he deemeth it good, (other than Satan's dupe)? Allah verily sendeth whom He will astray, and guideth whom He will
 Is it any wonder then that Islamic apologists and scholars have wanted to guard the secrets of the Qur'an by stressing the impossibility of translating it (in much the same way the Catholic church for centuries fought against translating the Bible into a language the common man and woman could understand. 

In his book al-Itqan, Al Suyuti says,
"It is utterly inadmissible for the Qur’an to be read in languages other than Arabic, whether the reader masters the language or not, during the prayer time or at other times, lest the inimitability of the Qur’an is lost.
 The same principle is followed by those who worked on the English authorized translation. They said (page iii),
"The Qur’an cannot be translated—that is the belief of traditional Sheikhs (religious leaders). The Arabic Qur’an is an inimitable symphony, the very sounds of which move men to tears and ecstasy." 
The Qur'an can be translated. It's just that when it is, the full extent and import of its errors become visible for all to see.