If a word is marked with an accent, then that syllable receives the
stress.
Additionally, if the accent marks a dipthong, a syllable break occurs
between the two vowels of the dipthong.
If a word is NOT marked with an accent, then:
1. If the word ends in a consonant other than N or S, the stress occurs
on the last syllable.
2. If the word ends in a vowel, N or S, the stress occurs on the next
to last syllable.
si = if
sí = yes
tu = your
tú = you
mi = my
mí = me
el = the
él = he
