I've lived in Spain for many years and speak pretty good Spanish. But there is one thing I still find relatively tricky in Spanish: the correct gender for nouns

I've lived in Spain for many years and speak pretty good Spanish. But there is one thing I still find relatively tricky in Spanish: the correct gender for nouns. The worst is when you're referring to something elsewhere in a sentence just by lo/la, well away from where the noun was, or have to make the adjective match the gender. If you get it wrong native speakers will not fully understand you or at least look at you weird. For Spanish natives, the "his/her" relationship word when referring to family members can cause problems, since the "his" refers to the other person, whereas su/suya in Spanish refers to the main noun. e.g. "hermana suya" - the "suya" is female because of "hermana" (or "su hermana" the "su" is neutral), whereas in English "his sister" the "his" is male because the other person must be male, the gender of the sister doesn't matter.