Compound Nouns 1: Noun + Noun

Compound nouns are everywhere! They are often composed of two nouns together, usually with a space between the words. When a compound noun is formed with two nouns, the first noun is generally describing the second one. For example: alarm clock. The second word, clock, is more general, and the first word, alarm, tells you what kind of clock it is. Here are some more examples of this kind of compound noun: credit card, sales department, youth hostel.
Sometimes the two nouns have come together and there is no space between them (although there may have been in the past). Examples of this would be: earring, trademark, sunglasses.
It's interesting to notice that compound nouns often appear in the language as a result of new inventions or new aspects of society. For this reason, they are constantly being invented.