Apex (diacritic)

Have you ever seen a little hat on top of a letter? That's called an "apex." It's a small mark that's sometimes added to certain letters in some languages, like Spanish, Portuguese, and Latin.

In these languages, the apex usually appears on the letter "a" or "e." It changes how the letter sounds when you say it out loud. For example, in Spanish, words like "él" (meaning "he") and "sé" (meaning "I know") have an apex over the letter "e." This makes the "e" sound a bit different than it normally would.

Sometimes an apex is also used to show emphasis in certain words or phrases. For example, in Latin, the word "prēsēns" (meaning "present" or "existing") has an apex over the second "e." This indicates that this particular syllable is emphasized when you say the word.

Overall, an apex is just an accent mark that helps change the sound of a letter or word in certain languages.