There are some rules, but the pronunciation is also important.
If the word ends in a vowel, an “n”, or an “s”, stress the last-but-one syllable:
If the word ends in a consonant other than “n” or “s”, stress the last syllable: ...
If the word has an acute accent, ignore the above rules and stress the accented syllable:
Answer:
That you didn't understand you
Explanation:
Ella Ensena with an accent mark over the n.
