Difference between expend and spend

Question

What is the difference between expend and spend. Both words have quite similar dictionary meanings

Expend:

spend or use up (a resource such as money or energy)

When to use which?

Answer 1

I cannot think of any obvious difference in meaning and they may be interchangeable, but there is a difference in usage with various words. Consider "spend effort" vs "expend effort, "spend money" vs "expend money", and "spend time" vs "expend time":

The only difference that I can think of to explain these differences in usage is that you can use up both time and money, but it is more difficult to use up effort -- you can always try harder. However, this is pure guesswork on my part.

You can experiment with other word combinations using Google Books Ngram Viewer.

Answer 2

I don’t know enough to explain this fully and there is very little difference in dictionary meaning and in some circumstances they might be interchangeable but in general usage, they are not.

Please consider a child with a sweet tooth:

“Dad; may I spend my pocket money on chocolate?”

Could “expend” reasonably replace “spend”?

Also consider in the boardroom:

What is our spending on widgets?
What are we spending on widgets?

What is our expenditure on widgets?
What are we expending on widgets?

Does that show that “spending” and “expending” are not always, if they are ever, interchangeable?

There’s a sense in which “one who spends his money on chocolate” is more present and “one who expends his money on chocolate” more continuous and that would be tenuous and archaic.

Today’s moralist might still moan about anyone “spending money like water” or “… like it’s going out of fashion” but it isn’t only the metaphors that are modern…

Can we see Dickens making Mr Micawber compare income with “spending” rather than “expenditure”?

Answer 3

I believe the general difference is that spend means the actual giving of money (or resource or time) whereas expend generally means to budget the giving of those things. While someone could expend money on the fly, the implication is that they did while considering a whole budget.

In the tooth fairy example: the little girl would be spending the money when she gave the cashier her 5 dollar bill in exchange for chocolate. If however, she considered that she had 5 dollars and a chocolate bar is a dollar, that would mean she'd only have 4 dollars left to buy a small toy that she wants, she would be expending that money for the chocolate bar.