Do you know what letters are? They are little things we write to make words. But sometimes we want to change how a letter sounds or looks. That's when we use something called a diacritic. A diacritic is like a little hat, dot or a line that we put on top, below or next to letters. It can make the letter sound different, or it can change the meaning of a word.
For example, in French there's a word "fete" which means "party". But if we add a little hat on top of the letter "e" like this "fête", it changes how it's pronounced and means "holiday".
In some languages, like Spanish, the diacritic looks like two little dots called "umlauts" that appear over letters like "u" or "i". They change the way the letter sounds.
Diacritics can also help us to know how to pronounce a word. For example, in English, the letter "a" can sound different in words like "hat" and "hate". But if we put a diacritic called "accent" over the letter "e" in "hate", it tells us to pronounce it differently from "hat".
So, diacritics are pretty cool, right? They may be small, but they can do big things and help us understand and communicate in different languages.