The Hebrew word 'Emet' and its derivatives are invariably translated as 'Truth' (capital T, generally). This translation is so ubiquitous that it seems silly to even discuss. Yet, I believe it to be a mistranslation, at least in certain contexts.
Take, for example, the first chapter in Rambam's Hilchot Yesodei Ha-Torah, where he uses the term 'Emet', in its various forms, several times. There, translating 'Emet' as 'Truth' obscures the meaning and makes things difficult to understand. Rambam's goal in Halakhot 1-4 is to describe how God's Existence is dissimilar, independent, and non-contingent on the existence of anything else, whereas everything else's existence is contingent upon His. Thus, compare the following translations:
"All existants, in heaven and earth and everything in between, would not exist but for the Truth of His Existence"
"All existants, in heaven and earth and everything in between, would not exist but for the Realness of His Existence"
"All existents are contingent upon Him, but He, blessed be He, is not contingent upon them or any one of them. Thus, His Truth is unlike the truth of any of them."
"All existents are contingent upon Him, but He, blessed be He, is not contingent upon them or any one of them. Thus, His Realness is unlike the realness of any of them."
Halakha 4 continues this trend, but there is no need to belabor the point. The Rambam here is not talking about what is True, but about what is Real.
Aside from general accuracy, I think that the difference between the different translations is profound. 'Truth' is an abstract concept that we essentially borrowed from the Greeks. They invented or discovered (not getting into that here) logical rules and postulates which allowed them to categorize statements as being 'true' or 'false'. Something which is 'True' corresponds to some kind of Ideal Form, and something which is false does not.
At some point, the Hebrew terms 'emet' and 'sheker' came to correspond to these Greek concepts. As we got used to the Greek way of thinking, it was important to have the vocabulary to communicate it. The problem is obviously that it ends up 'Hellenizing' ideas and statements that appear in early Jewish works. Those early sources are not necessarily concerned with abstractions. The Torah and the Neviim, and Chaza"l in their wake, are amazingly concrete, often expressing abstraction in very 'earthy' ways. They were interested in what's real and what's fake, what's authentic and what's phony, what's orginal and what's imitation. The problem with lying is not the violation of some abstract category, but the representation of something which is misleadingly non-real.
I'm not suggesting to stop translating 'Emet' as 'Truth', just that the other possibility be tried as well, because it might make a big difference.