Sorry, I was caught in a tp ambiguity, what the scope of a question is. ‘mi sona e ni: sina kepeken e nimi ‘, tan seme’ makes the whole complex sentence + display appear to be a question. It is an odd one, to be sure, since we don’t ordinary say we know something that we are questioning. But you might have been using ‘sona’ as a variant of ‘pilin’, say, and so a matter of “wonder”. I now realize that you were, in fact, trying to reproduce an English (or German, as far as I can recall -- it’s been 60 years) “indirect question” “I know why you use apostrophe”. This, of course, is not a question and. contains no question, merely a relative pronoun, which is externally identical to an interrogative one (and has been alas, for 5000 years). Translators (to languages which don’t have the same congenital disease) have learned to deal with this. So, what you meant was simply ‘mi sona e tan pi kepeken nimi ‘’ “I understand the reason for using apostrophe.” I confess I am not as thorough at cleaning up this particular mess as I should be, so too many cases of calquey passages have slipped through and I got caught by one of them. Sorry to have not caught it sooner and to have fed you a second dose of something that you already knew and, I hope, thoroughly disapprove.