The idiom "bark up the wrong tree" means to make a mistake by directing your efforts or accusations towards the wrong person or thing. It is often used when someone is trying to find the source of a problem or trying to assign blame, but they are looking in the wrong place.
For example, if someone accuses their coworker of stealing their lunch from the office fridge, but it turns out that it was actually someone else, they would be said to have "barked up the wrong tree."
The origin of this idiom comes from hunting dogs who would bark at the base of a tree where they thought their prey was hiding, but the prey had actually climbed a different tree.
In everyday conversation, you can use this idiom to gently correct someone who is mistaken about something or to caution someone against making assumptions without all the facts. For instance, if your friend accuses someone of being rude to them, but you know that person is actually very polite, you could say "I think you're barking up the wrong tree there."
• The customer accused the sales assistant of stealing her purse, but she was barking up the wrong tree as the purse was found in her car.
• The government accused the opposition party of spreading false rumors, but they were barking up the wrong tree as the information was leaked by a whistleblower.
• The scientist thought he had found the cure for cancer, but he was barking up the wrong tree as further research proved his theory to be incorrect.
• My friend thought I knew where the party was, but he was barking up the wrong tree.
• The detective thought the suspect was the murderer, but he was barking up the wrong tree as the evidence proved otherwise.
• The journalist accused the company of corruption, but he was barking up the wrong tree as the company had no involvement in the scandal.