Using could have to talk about the future

Question

I’m wondering if you can use could have to show that a future event was possible in the past, but it won’t happen anymore. For example, I have some work to get done before my vacation ends and I’m planning on doing when I get back to my home town in two days. I then get a call from my friend and he says that he finished the work. I then say to him I could have done it when I get back. Is the last sentence correct? I could have done it when I get back seems like it should be when I got back, but that’s not what I’m trying to say. If you can’t use could have to talk about a future event that was possible in the past but won’t happen anymore, then is there any correct way to do it?

Answer 1

Hi Keven. You are on the right track. The correct tense is to say I could have done it "when I got back," as you suggested. In this instance, you are using "could have" to talk about the "past event" of your friend having decided to do the work already. So, in that instance, you are not using "could have" for a future even, you are using it to describe a past "scenario" that could have happened...had your friend not decided to do the work. Also, if you wanted to be a bit more formal, you would use "returned" instead of "got back."

Let me know if you need more clarification.

Dan

Answer 2

You're on the right track in thinking about how to express a past hypothetical scenario, but "could have" is not typically used for a future event that was possible in the past but won’t happen anymore. Here’s why and how you could phrase it differently.

In your example, if you say, “I could have done it when I get back,” it feels off because "could have" inherently refers to a possibility in the past that didn't occur. Once you use "could have," you're locking the hypothetical event into a past timeframe—even if you're talking about an upcoming return. So the sentence becomes confusing because it mixes past possibilities with a future action.

To make this clearer, you could try a slight rephrasing:

1. “I would have done it when I got back.”
2. “I would have taken care of it when I returned.”

These alternatives use “would have,” which conveys your intention to do the task if things had been different. If you need a way to clarify that this is about your future return, you can add a phrase like "if you hadn’t done it."

This revised phrasing gives you a natural way to express the original thought without conflicting tenses and focuses on your willingness to do the work if the opportunity had been there.