Hurray! Yipee! Wowee! Let’s hear it for my favorite part of speech: the interjection! Interjections help to express emotion on the part of the speaker in written language. They are usually separated off from the rest of a sentence by commas or exclamations points. In any language, interjections make the written word more expressive.
Here is a list of my personal favorites in a few different languages:
¡Ojo! (Watch out!)
Ja ja ja (Ha-ha-ha)