The three sentences you see provided above are excellent ways to express to your listener the reason why you drink only water. In the first two sentences you will notice the words stain and discolor and in the third sentence you will notice the term make something dirty. These two words and this term mean to mark something, normally to the point that it is difficult or impossible to remove.
You don't get stains when you spill water but you do with juice
「例えば、水はこぼしても乾いたらシミになったり汚れないだろ？ジュースの場合は汚れるじゃん。」
"For example, even if you spill water you won't get *like stains when it dries right? With juice though, you do."
*染みと汚れはほぼ一緒の意味なのでシミや汚れやを一つに表現してます。
若者の間で良く使いますが特に使わなくても良いです。
When you want to contrast two things you may use a variety of linking words or phrases such as: but, however, on the other hand, whereas etc.
"John is left handed whereas Peter is right handed."
二つの事柄を対比させたいときには、いろいろな接続詞が使えます：
but, however, on the other hand, whereas etc.
例文
"John is left handed whereas Peter is right handed."
（ジョンは左利きだが、ピーターは右利きだ）
In American English, we often say substances are 'sticky' if they leave a residue that adheres to skin and is difficult to wash off. We use the phrase 'leave a mess' to talk about someone or something that 'creates disorder in the wake of their actions', so a parent might say to a child: 'Clean your room and don't leave a mess behind.' This is to be contrasted with the phrase 'make a mess', which indicates the actual process of mess making. I hope this is useful to you in your ongoing study of the English language.
アメリカ英語では、触れると皮膚に洗ってもなかなか落ちないかすが残る物を、よく 'sticky' という言葉で表します。
が残り洗ってもなかなか落ちないとき
'leave a mess' は混乱を残す人やものについて使われます。ですから、親が子どもに対して次のように言うかもしれません。
'Clean your room and don't leave a mess behind.'（しっかり部屋を片付けていくように）
これは 'make a mess' とは対照的です。'make a mess' は実際に散らかす行為を指します。
お役に立てば幸いです。
"Water doesn't leave a mess"
'A mess' is considered something that is unclean, dirty, a stain etc.
This sentence implies water is clean and will not make anything unclean/look unclean.
"Water won't stain"
Simple phrase, to 'stain' is to permanently discolor a particular surface, such as a T-shirt with a red wine stain.
"Water doesn't leave a mess"（水は汚れが残らない）
'A mess' は、汚いもの、シミなどを指します。この文は「水はきれいでほかの物を汚さない」という意味合いです。
"Water won't stain"（水はシミにならない）
シンプルなフレーズです。'stain' は、例えばTシャツに赤ワインをこぼしたときのように落とせない跡が残ることをいいます。
Water doesn't make any mess compared to what juice does if it spills.
"Water doesn't make any mess compared to what juice does if it spills" - This explains that even if you do drop your water over the floor or on your clothes it will not get dirty/stained.
Example - "Dropping the juice on the floor has made a bad mess"
"Water doesn't make any mess compared to what juice does if it spills"（ジュースはこぼすと汚れるけど水はこぼしても汚れない）
は「水はたとえ床や服にこぼしたとしても、汚れになることはない」と伝えます。
例：
"Dropping the juice on the floor has made a bad mess"（ジュースを床にこぼして大変なことになっている）
Juices are different colours and sometimes contain alot of colourings which can stain things if the juice gets on them whereas water is clear and has no colour so although it makes things wet it does not stain or colour them
アメリカ合衆国 
日本 
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