Recently I wanted to learn the equivalents to the common money-related verbs of English such as buy, pay, sell, and spend.
I found two words for "spend" and would like to know what the difference is between them, whether one is better for "to spend money", whether one is common and the other rare, etc:
In brief, 費やす is used to say something was used badly (wasted/squandered). Unless that is what I want to communicate, I refrain from using it.
I see that my dictionary (プログレッシブ英和）gives two meanings: one to spend and one to squander - see examples below - but for the sake of clarity I suspect most people follow my practice (but am open to comment).
Examples:
Spend
毎日30分を英語のヒアリングの練習に費やしている
I spend 30 minutes every day trying to improve my aural comprehension in English.
彼はその本を書くのに3年の労力を費やした
It took him three years' hard work to finish the book.Waste/squander
つまらないことに時間を費やす｜waste time doing unimportant things
宝石に無駄な金を費やす｜waste [squander] one's money on jewelry
