ACTIONS SPEAK LOUDER THAN WORDS means that what someone says is different from from what they do. It is often used when someone makes a promise but then doesn’t keep it.

For Example:

“Dad, I promise I’ll be on time for class and do all my homework as soon as I get it.”
“Well that sounds great, but actions speak louder than words. Lets wait a couple of weeks and see if can you really do it.”

“The director has been promising to hire a new teacher for two months, but we’re still working overtime with no extra pay. I’m going to tell him that actions speak louder than words, and if he doesn’t get a new teacher in 2 weeks, I’m getting a new job.”