I am trying to figure out what the most proper way for one to say something simple like if someone asked, "How do you know that?" and then I say, "I read it in a book". Now what I'm wondering about is how you translate that "I read a book" clause into Mandarin.
See, the "read" here is a past tense, and apparently, in Mandarin, there is no "tense" marking. Time, it seems, is indicated by putting a time adverbial before the verb. Yet here there is no specific time, rather it's at some indeterminate past time, the only thing known is that it happened. My best guess from various reading material was to try something like,
我以前看一本书 (wo yiqian kan yi ben shu),
but that seems to my ear to lay really heavy emphasis on the "past"-ness of this action, when that is not the primary point here, the point is the fact of having read the book.
So what I really feel I want to do is to use
了, as in
我看了一本书 (wo kan le yi ben shu)
But then I hear that 了 "is not a tense marker", "has nothing to do with time and nothing to do with tense" and stuff like that, and that what it really indicates is "completion". Yet the English sentence has tense. So is the above the correct way or not? I also think that the first sentence I mentioned should be
我以前看了一本书 (wo yiqian kan le yi ben shu) as well, but there the 了 seems less troubling to me because we have the time specified and in the sentence
我看了一本书 given out in this context it seems to my ear that 了 is acting like a tense marker, setting up a contradiction. Without 了 I get
我看一本书 (wo kan yi ben shu)
which sounds to me more like "I read [pronounced REED] a book", but then again I've heard that tense/time can be inferred from context.
If the form
我看了一本书 is correct then what role is 了 playing here and why does it sound to me like past tense with a not-a-tense-marker indicating tense?
If none of these are correct, what, straight up is the correct translation? I've found it really hard to find something that just straight up answers that.
(Also, I'm not 100% sure if the counter 一本 indicating the singularity of the book is needed or correct in all these either but that's a separate question! This question is about time/tense not measure and I'm just using that as an example of something where I think the time is not indicated elsewhere in the conversation by any grammar feature.)