If I want to say
John studies at home and the library
do I say
ジョンさんはうちととしょかんでべんきょうします。
I feel like I'm getting the particles wrong or that I'm actually supposed to use double particles.
If I want to say
John studies at home and the library
do I say
ジョンさんはうちととしょかんでべんきょうします。
I feel like I'm getting the particles wrong or that I'm actually supposed to use double particles.
「ジョンさんはうちととしょかんでべんきょうします。」
This sentence is grammatical but it does not sound very natural for a couple of reasons.
1) Use of 「うち」. In this sentence, the speaker is NOT ジョン. When native Japanese-speakers hear just 「うち」, we would tend to think it refers to the speaker's home as @broccoli forest states in the comment above.
To avoid that, you can use 「[自宅]{じたく}」 or 「[家]{いえ}」 instead of 「うち」.
2) Use of 「と」. I am sure you just directly translated "and" and came up with 「と」. As I said, it is grammatical, but the native speakers's word choice would be 「や」 considerably more often than 「と」.
If you think you are required to use 「と」 in your class, I will not beg you to use 「や」.
(「うち」, however, I must advise that you not use.)