Tricky Words in this week's OVI

Spare and save. These two words originally meant the same, "spare" deriving from German and "save" from French, and the basic idea is the same as "šetriť". In Slovak there is also "sporiť", however, and this is where confusion could arise.
"Sporiť" is related to the German "sparen" (the German equivalent of "sporiteľňa" is "Sparkasse"), but in modern English the idea is "save money" (in BrE there is "savings bank" and in AmE there is "thrift institution", thrift coming from the Old Norse idea of good money management, economy producing profit).
You can save money, time, water, electricity. When there's no point in talking about something, you should "save your breath" ("šetri si dych!"). But now it changes: a paramedic rescue team can save somebody's life, which means "zachrániť" rather than "šetriť", whereas to spare somebody's life means to let somebody live when they have otherwise been condemned to death, like in ancient Rome when Caesar gives the "thumbs up" sign to let a defeated galdiator live.

Andy's Wordshop

Going on with "spare", if you have something spare, that means you don't need it at this very moment, so it's like "navyše" or even "nadbytočné". Spare cash is money you can give away if you want.
There's a famous old American song (and film) called "Buddy, can you spare a dime?" The spare wheel in older cars is the extra wheel in the trunk which you need if you have a flat (tire). A spare room in your house is either full of old belongings, or it's a guest room for visitors to sleep in. This is the modern sense of "spare", but there are some fixed expressions in English which keep the old idea of "šetriť", like to "spare your efforts", which means to reduce, or not to waste them (like "save"), or to be "sparing with words" (skúpy na slovo).
In cooking we're advised to use salt "sparingly" (šetrne).