Could anyone tell me what the meaning of "-t-" in these sentences is? Avec l'article definir, que se passe-t-il? Conbiem de fois y utilise-t-on la conjonction ni?
There is absolutely no meaning to -t-. It's there to make it easier to say and to avoid two vowels from colliding: passe-il (e-i) and utilise-on (e-o). The french don't like their vowels colliding.
For someone who's learning french, there are a lot harder words to say than passe-il and utilise-on but we don't have a say in how their language should be :-(
Think of it like how we say "a banana" and "an apple". It phonetically enhances the language.
It means nothing. It's added when an inversion occurs and the second word begins with a vowel that can't be linked with a 'liaison' with the first word, so an artificial one is created by including that 't'.
A liaison is when a word ends with a consonant and the next one starts with a vowel and both sounds are linked phonologically. For example, when you pronounce 'ils ont' like ' il zon', linking the last 's' with the initial 'o' of the conjugated verb.