Without knowing exactly what you're referring to, I risk answering the wrong question. Standards of translation vary over time and with the skill of the translator. In particular, a lot of the free (out of copyright) translations available on the Internet today are a bit, erm, more purple than modern scholarly translations that you have to shell out $$$ for from Brepols or Brill. Medieval language, especially certain varieties of Latin text, does not always lend itself well to "direct translation," so there can be quite a bit of room for interpretation and changing linguistic norms in translations.

That said, the question of "what medieval people talked like" is a fascinating puzzle that can only ever be approached asymptotically, never known for absolute sure--even in cases that purport to be recorded/dictated speech.

The first barrier to approaching medieval speech patterns in the use of Latin. It is important to note that the problem of Latin writing versus speech isn't primarily a problem of "Latin the dead/written language" versus the spoken vernacular. Clerks, monks, and nuns writing in Latin were frequently absorbed in Latin speech as well, often from childhood. University scholars were required to speak only Latin, a phenomenon which appears in records frequently when students get into trouble for not. By the time they completed university work, however, the people who did so much of the surviving writing in the late Middle Ages were capable on-the-fly speakers of Latin.

However, the learning of Latin brought with it a couple of wrinkles that do set it apart from medieval vernaculars. First, the basic instructional book for Latin in the Middle Ages was the Psalter. That is, a book of poetry. The Bible as a whole was not far behind for people who learned primarily in and for a monastic convent, both through reading and through hearing and singing in the liturgy. Writers with a monastic background, whether that means university scholars like Bonaventure or visionary nuns like Gertrude of Helfta, weave Scripture verses in and out of their prose as if unthinkingly--their daily, intimate experience with the language of the Bible colored their writing that much.

Second, in the case of those who went on to more advanced study of Latin for composition rather than religious edification through reading and liturgy, the art of rhetoric formed an integral component of their education. Although humanists of the fifteenth and sixteenth century deplored the "decayed" rhetorical standards and education of many medieval writers, the actual situation was less a discarding of classic rhetoric as a channeling of it. Rhetorical principles of composition, which survived in the Middle Ages especially through a set of writings (wrongly) attributed to Cicero, were put to use not for the production of clever and awe-inspiring oral composition but rather to help listeners of sermons memorize the lessons better. But the use of rhetorical techniques to build sermons and written literature in a particularly compelling (for the memory) way introduces a major "artificial" component to the composition.

This is particularly noteworthy because very much of medieval recorded speech is, actually, sermons. Bonaventure's Collationes in Hexaemeron, or collations/sermons/speeches on the six days of creation, survives as essentially a dictation (through notes taken by listeners). But this reflects his training as a writer of religious literature and scholastic sermons, not his speech.

The big-R Renaissance humanists who complained from their lofty Latin and Greek perches about the decayed state of medieval Latin rhetoric, however, were on to something. One of the phenomenon in later medieval Latin texts that makes some of them (some of them) a bit easier to translate for modern people is the infection of classical Latin with--horror of horrors--vernacular word order. Although sentences can still be monstrously long, to translate them word for word yields something closer to early modern and modern patterns of English, French, German (still with sufficiently large piles of ablative absolutes, but fewer than you would see in classical Latin). This particular phenomenon is actually visible back to antiquity among writers with a less advanced rhetorical education. The majority of the Passio Perpetuae (Passion/Martyrdom of Perpetua and Felicitas) was written by Perpetua herself, and it is one of the easier Latin texts to translate because it does not play by as many of the rules of classical rhetoric that result in windier prose. Does that make her words closer to speech? It seems likely.

The late Middle Ages introduce the problem of the vernacular onto the scene with a vengeance. (There is of course vernacular writing earlier; it's just vastly more prominent and coming from more levels of society in the late period.) Not only are people more likely to be writing in the language they grew up speaking or something close to it (dialects are funky), but scholars into the sixteenth century continue to debate the suitability of the "vulgar tongue" for prose and verse composition. It takes awhile, in other words, for vernaculars to be something taught for the purposes of creative composition rather than religious edification or brute practicality. (Dante, who unquestionably used the vernacular for glorious creative composition suffused with classical learning, for example, is also famous for writing a defense of Latin in Italian and a defense of Italian in Latin).

Many of the late medieval vernacular writers with which the English-speaking world is most familiar in school--Chaucer and Dante probably being the most prominent--suffer from a twofold handicap in terms of getting at speech. First, we study them in complete or partial translation. Second, these are people with a flabbergasting amount of education compared to the standards of their day, who are (like Dante) frequently making a politicized point about the utility of the vernacular for literary use as well as practical matters. Chaucer often gets praise for the earthiness of his language as a way to "get at" medieval standards of swearing and obscenity, but it seems, shall we say, highly unlikely that the Middle Ages were full of peasants and burghers running around shouting at other in rhyming couplets.

Not all late medieval vernacular writing, however, is verse, and not all of it has literary-political goals. I spend a lot of time with late medieval German religious writing, which is frequently terrible. One of the problems I have when translating it in my own writing, in fact, is just how basic it can sound.

The following Lent I was sick again from teh same illness already described, which I have during every Lent. Fourteen days before Easter I was bedridden as usual. During those fourteen days I lay there without being able to speak a word. Even if I wished to speak I could not. My mout was so tightly closed that I could not pray.

or

There are three person, whom you should serve and not make mad. The first person is God, the second is yourself. You should love yourself, but through God. The third is your neighbor. You are responsible to have love towards your neighbor and do right by him. But you must love yourself more than your neighbor and God more than everything that is in heaven and on Earth. When you sin against someone, who is your childhood friend or who has done right by you, that is worse than if you act against a stranger. God also has friends. When you sin against them, that is even worse.

Margaret Ebner in the 14th century and Johannes Nider in the 15th have vastly different levels of education and are writing for vastly different purposes. Ebner is composing writing, for her spiritual friend Heinrich von Nordlingen; Nider is composing speaking, a sermon for the nuns and (probably) semi-nuns of Nuremberg.

That is not to say that either sample is what you'd find if you bumped into Ebner in her cloister or confronted Nider about his hypocrisy in vigorously supporting some religious women while virulently condemning others. Each of them wrote for a purpose with a goal. But while neither example approach "everyday speech," they do point to the diversity of medieval prose patterns that are recorded. We can see similarly abrupt rhythms, overuse of transitions like "also...also...also," and other what we might call speech-like patterns in court transcriptions, such as the minute (record) from Joan of Arc's trial. Even though the scribe carefully couches everything in "she said" "she answered" "she said," and he is translating from her French to Latin, the trappings of classical rhetoric are shed.

It may seem pointless to drag out this answer into such a complex investigation of the "common sense" idea that of course people didn't talk like that. But--as records of collationes like Bonaventure's Hexaemeron, or the books of Gertrude of Helfta's Herald of Divine Love that were surreptitiously recorded by her fellow nuns indicate, sometimes medieval people did talk in flowery language.

Thus, by investigating other patterns of textual survival for different rhythms of writing, we can peer beyond the influence of Jerome's Vulgate (medieval-preferred Latin Bible) and the survivals of classical rhetoric to see different ways that medieval people at least thought in words and used them to communicate.