"THEN" and "THAN"

"Then" relates to time. "Than" is used for comparison. Ex.: First, we'll have lunch, and then we'll go for a walk. He is more experienced than I am.

"PEEK," "PIQUE," and "PEAK"

"Peek" means a quick look. "Pique" means to provoke or arouse. "Peak" refers to the highest point. Ex.: Let's take a peek at the menu. Her curiosity was piqued. We reached the mountain peak at noon.