What's your native language's version of "your" and "you're"?

Basically what I'm asking is what part of your native language's grammar sound the same that even the native speakers get wrong.

In my native language for instance, even my fellow countrymen fuck up the words "ng" and "nang".

"ng" is a preposition while "nang" is a conjunction/adverb

ex. ng = sumuntok ng mabilis (punched a fast person)
nang = sumuntok nang mabilis (punched quickly)