Can we say "do an action"?

Question

When we use "action" as an uncountable noun, the collocation is "take action" or "go into action." How about when we use it as a countable noun? Do you think it is okay to say, "do an action"? And can we use any other words than "do"? Example sentences:

Don't just wait. Do an action. (Context: Telling someone to do something instead of just waiting)

The teacher needs to do the action to display how to do it to students instead of just telling them what to do. (Context: Talking about a CPR teacher)

Note: I am asking this because I couldn't find the right collocation in a dictionary.

Answer 1

I would go for perform an action, and Google Ngram seems to confirm that it's more often used than do an action or any other alternatives I could think of, both for the indefinite (an action) and the definite (the action) variation.

But in your first example, "Do something!" is more idiomatic, or perhaps even "Act!" (it is a verb too).

Answer 2

Normally we do not say we are doing an action. Each of those words, do and act, implies the other. If you do something you have acted. If you have acted you have done something.

In some situations, such as your second sentence which is a very nice example, we do want to refer to doing an action but we only need to mention it once. If the teacher was showing a video or a graphic of someone else performing the action we might say she was displaying how to do it. If the teacher is physically performing the action, we would say she is demonstrating how to do it.

The teacher needs to display/demonstrate how to do the action instead of just telling the students what to do.

Even in the case above the words the action are very vague and generalized. It is a bit odd for me to think of referring to a specific thing using the word the and follow it up with a word as generalized as action. I think in actual conversation I might be apt to select a different word, one that more specifically describes the action.

The teacher needs to demonstrate how to clear the airway instead of just telling the students what to do.

In your question you specifically mention countable actions. Whereas I would be more likely to refer to a specific, countable action by the name of the action itself, clear the airway for example, I would feel comfortable referring to each action or an action as a way to identify an entire, countable series of actions or a non-specific action within that series.

The teacher needs to demonstrate each action instead of just telling the students what to do.

Answer 3

"Do an action" is not common in English, and I can't think of any examples where it would be appropriate. Typical phrases that would be used might be "Take an action", "Perform an action" or "Demonstrate an action".

Your first example is difficult to apply to the countable noun; potentially you could be encouraging someone to choose an action, or to perform an already chosen action. In either case, though, someone speaking/exhorting the person would likely not use a phrase like "choose an action", but would probably say something like "Come on, do something!" or "Don't wait, just do it!".

Your second example has been covered quite well by Ellie; 'demonstrate' is the most appropriate word and allows the sentence to be shortened, e.g. "The teacher needs to demonstrate [the/each] action instead of just telling the students what to do.".

A common situation where 'action' is a countable noun is when playing a board game, and you will often hear phrases such as "Pick an action", "Use an action" and particularly "Take an action" used in that scenario. Possibly even "Do an action", but it still feels awkward/incorrect.