"Chuir sí plandaí sa pháirc."
Translation:She planted plants in the park.
I got it right. Let's see "Sa" when the following word begins with a consonant, "San" when the word following begins with a vowel, and "Sna" when the following word is a plural. Anything I missed? :)
It’s san when the following word begins with a vowel sound, so you need to keep an eye out with a lenited F to look at what the next sound is, e.g. san Fhionlainn (“in Finland”) but sa Fhrainc (“in France”).