Beat a dead horse

Used when someone brings up a topic repeatedly with no chance of affecting the outcome.

Straw that broke camel’s back

When something is filled/loaded up beyond capacity. Used in when something is thought of as the last in a line of unacceptable occurances.

Grasping for straws

Used when the someone is trying to find reasons to feel hopeful about a bad situation.

Stick in the mud

Used to describe a person who doesn’t want to participate in activities suggested by others. More generally, one who is slow, old-fashioned, or unprogressive.

Chip on shoulder

A person who has ‘a chip on his shoulder’ is angry because of some thing that happened in the past. Example: “He lost his game this morning, and now he has a chip on his shoulder.”

Pigeon-holed

To treat or classify according to a mental stereotype. For example “In my new job, i’ve been pigeon-holed as a front-end engineer”.

Ear to the ground

Something similar to observing closely. For example “ I’d like to be located in the main office where I can have my ear to the ground”.

Coming up for air

When some tries to tell you that they’ve just taken a break from some continuous activity, and are surfacing to get some relief/change.

Like pulling teeth

Something very complicated/painful/difficult to do, especially to extract information from someone. For example, “It’s like pulling teeth to get a straight answer from him.”

Dont want to burn any bridges

Means the speaker doesn’t want to harm any existing relationships with prior acquaintances