What is an accent mark look like?

It depends on what kind of accent mark you're thinking of! There are many different accent marks used in different languages. Here are some of the most common ones:

Acute accent: ´ (like in café)

Grave accent: ` (like in été)

Circumflex accent: ^ (like in hôtel)

Tilde: ~ (like in mañana)

Diaeresis: ¨ (like in naïf)

Cedilla: ¸ (like in garçon)

These accent marks are all written above the letter they modify, but their shape and position can vary.

Can you give me more context about the accent mark you're interested in? For example, what language are you thinking of? Or is there a specific word you're looking at?