Question: I am looking over something before posting it online and I have a sentence that simply doesn't seem to 'sound' right either way I write it. Specifically, I am trying to decide whether it is more correct to use 'oasis' or 'oases' in the sentence below.

There are two types of [oasis/oases] in the world.

If it makes a difference, these are metaphorical oases.

Thank you in advance for your help!

Answer: 
The plural of **oasis** is **oases**, which you should use if you have more than one:

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> There are two types of oases in the world.
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But if that doesn't sound right to you, make it singular:

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> There is more than one type of oasis in the world.
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In a comment, John Lawler wrote:

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> This arises with any word; *There are two types of mountain/banana/book in the world* versus *There are two types of mountains/bananas/books in the world*. Both are correct, singular or plural; there is no difference in meaning. Just speaker's choice, like most such choices.
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