I'll think of something / I'll make something up

Question

My brother's sneaking out to a party and before leaving he asks me what I'm going to tell our parents when they ask where he is. I say:

• I'll make something up.
• I'll think of something.

Do both the expressions mean the same thing?

Answer 1

In this context, they are interchangeable.

"I'll make something up" places greater emphasis on the fact that you are lying.

"I'll think of something" does not necessarily mean you are lying (although in this case, the context makes it clear that you are): it can mean "I will choose a truthful reason that makes a good excuse."

Answer 2

Out of that context ( with the example above) 'I'll think of something'means to come up with an idea that is factual eg. What shall we do on Sunday? I don't know, I'll think of something.

Whereas to make something up would not work there. To make something up always means to pretend, or create fiction, like making up a funny story. And yes it can mean to lie.

Answer 3

The two phrases are not quite interchangeable. "I'll make something up" suggests that you plan to come up with a fabrication (lie), and are not planning to tell the truth.

"I'll think of something" could mean either something factual (tell the truth) or that you might still come up with a lie. It's a bit vague. "I'll come up with something" is very similar.

Given the context (sneaking out to a party without parental permission), it might be very hard to come up with a completely truthful explanation that will get your brother off the hook. Given such difficulties (particularly if you are facing punishment if you lie), the implication is that you are acknowledging that you will have to lie to cover up for your brother, even though (with the "think of something" phrase) you aren't yet committing to a lie.