Look up a word in the dictionary: depending on what you mean, you have various possible definitions. This is true for most words in all languages, and a sentence or a short paragraph is not necessarily enough to clarify what the exact meaning of a word is. This is why context is so important for translation: it is about meaning (in context) rather than words (in isolation). As a result, the shorter the text, the more time it is likely to take, proportionally speaking, and it is therefore vital that you inform your translator about the background beforehand.
A translation agency once commissioned me for one short sentence – yes, just one sentence. You might think that it would be a two-second job, and that was indeed what the agency said, but it wasn’t. (Is there ever such a thing?) I had to call the agency back to ask what the context was. What sort of “account” was this about? A bank account, a customer’s account, a person’s report of events…? Depending on the meaning, there were 5 possible translations. The agency didn’t know, it was nearly 6pm, the client had gone for the day and of course it was needed for the next morning first thing. So I supplied all possible solutions with a brief explanation for each so the client could choose according to his/her needs. All in all, this one sentence took a good 20 minutes due to a lack of information – an issue the agency could have foreseen.
In contrast, a (favourite) client of mine recently asked me to translate a few sentences for her website that a previous translator had omitted. She sent me the whole text from the page in Word, highlighting the omissions to be translated, so I could ensure consistency. I was therefore able to deliver an accurate translation quickly without wasting her time or mine with avoidable questions.
Updating a document by changing a few words is also far more involved than may be anticipated. If the word changed is referred to as “it” throughout the rest of the English text, this has no consequence. In the other language, it is likely to have a domino effect on the sentence or even the paragraph due to gender and/or plural agreements with many other words around. This seemingly minor change can require the whole text to be updated. One word at your end could mean half an hour’s work at our end.
A text functions as a whole unit. Minor changes are everything but “two-second” tasks. Finalising your text before submitting it to your lovely translator and giving adequate context for small pieces will save you time (and money, and headaches…) and will keep everyone involved happy ever after.