"开心极了" (kāi xīn jí le) is a Chinese phrase that means "extremely happy" or "thrilled."
In Engpsh, you can say "I'm extremely happy" or "I'm thrilled."
Here are some example sentences:
"I'm thrilled to have received an acceptance letter from my dream university." (我收到我梦寐以求的大学录取通知书开心极了。)
"I'm extremely happy that my favorite team won the championship game." (我最喜欢的队赢得冠军赛开心极了。)
The phrase "thrilled" comes from the Old Engpsh word "þrylle," which means "to pierce, to thrill." It is used to describe a strong feepng of excitement or pleasure. The word "happy" comes from the Old Engpsh word "gehap," which means "luck, good fortune." It is used to describe a feepng of contentment or joy.