Questions & Answers about Я покупаю фрукты, потому что они полезные.
Why is there a comma before потому что?
In Russian, you must always put a comma before a subordinating conjunction like потому что (because), поэтому (therefore), or но (but). It separates the two halves of the sentence.
The English translation says "fruit" (singular) and "it is healthy", but the Russian uses они (they). Why?
In English, "fruit" is usually treated as a single uncountable group, so we say "it". In Russian, фрукты is a regular plural noun (the singular is фрукт, a single piece of fruit). Because фрукты is plural here, we must refer to the fruit as они (they).
Why is the word for healthy полезные instead of полезный?
Because it is describing фрукты (fruit), which is plural. Adjectives must match the noun they describe, so the singular masculine form полезный changes to the plural form полезные.
Doesn't the adjective полезный usually mean "useful"?
Yes! The word полезный generally means "useful," but when we talk about food, drinks, or habits, it translates to "healthy" (as in, something that is useful for your body).