The verbs “spend” and “expend” are synonymous in the sense of using up or paying out for something, but they differ in the purpose of or expectation from the act. To “spend” is to use up or pay out for something without a deliberate purpose or conscious expectation of a return from the spending; in contrast, to “expend” is to pay out or make use of money or some resource for a specific purpose or return from the expenditure. Generally, then, spending is done habitually or freely or as a matter of course, as in the sentence “They spent most of their allowance on video games,” while expending is deliberate and purposive, as in the sentence “They expended most of their savings in the education of their children.”
