Philosophers discuss at length what truth in a sentence means. Not, as you might expect, a circular argument since they are presumably using sentences to discuss the matter. In a way what they are trying to gauge and understand is what, if anything, is assumed in allowing us to communicate at all with words.
One of the main breakthroughs in thinking about this was to link truth and meaning. But the route to doing this is not obvious, as this is not about what the sentences mean to you or me but what they mean irrespective of you and me. One way to think about it, though not a good one, is to conceive of a sentence as a translation of the meaning it conveys and the translation takes meaning and puts into grammar. Then those rules of grammar are learned and we begin to understand what is being said. The understanding presupposes a huge amount if intellectual power to learn wordsand to what those relate in the world, and syntax – which is why we take so long to learn to speak.
The consequence of this is that a sentence can be true. It can also be true as a sentence while being mendacious as a concept. This is not about ‘truth’ but what it takes for a sentence to be a sentence that is true.
In other words we can lie to each other in perfectly correct sentences.