If you don't eat it all, please give me your leftover pizza!
・you don't eat it all 「すべて食べられなかったら」
という表現を使っても、自然な英語になります。
例）If you don't eat it all, please give me your leftover pizza!
「もし、全部食べ切れなかったら、残りのピザをください」
Leftoverが残り物という意味になるので、leftover pizzaで残りのビザという意味になります。
ご参考になれば幸いです。
Spare = give (something of which one has enough) to (someone), afford, do without, manage without, get along without, dispense with, part with, give, let someone have, provide
"She asked if I could spare her a bob or two"
Chuck something = to throw something in a careless or relaxed way
chuck something on/out of/into etc something
"Tania chucked her bag down on the sofa."
" I chucked a few things into a suitcase and left."
Spare =（誰かに）すでに十分で余裕のあるものを与える、余裕がある、～無しで間に合う、分配する、分け与える。
例："She asked if I could spare her a bob or two"
（彼女は私にいくらか借りられないか頼んだ）
Chuck something = 軽く投げる／譲る、ポイっとする。
chuck something on/out of/into
例："Tania chucked her bag down on the sofa."
（タニアはカバンをソファに放り投げた）
" I chucked a few things into a suitcase and left."
（私はいくつかの物をスーツケースに詰め込んで立ち去った）
If you don't finish your pizza, can I have some of it?
Would you mind if I have your left over pizza?
Can I have a piece of your pizza?
>If you don't finish your pizza, can I have some of it?
*This asking a friend that if he/she does not finish the pizza if you can have of it.
.......................
>Would you mind if I have your left over pizza?
*This asking if the person would be upset if you have the left over pizza.
.........................
>Can I have a piece of your pizza?
*This is a simple way of asking a friend if you can have of their pizza.
.................................***.................
If you don't finish your pizza, can I have some of it?
友達にピザを食べきれなかったらもらいたいということを尋ねる表現です。
Would you mind if I have your left over pizza?
残っているピザをもらうことができるか尋ねる表現です。
Can I have a piece of your pizza?
友達にピザが欲しいということを尋ねる表現です。
Is it alright if I have a piece of leftover pizza?
"Can I eat whatever is left of the pizza?" is a question that clearly asks someone if it is possible if you could have some pizza that is leftover once they are finished.
"Can I eat whatever is left of the pizza?"
（余りのピザを食べてもいい？）
という質問文は、「もし余りが出たらもらってもいいか」ということを明確に尋ねることができます。
That pizza was delicious. Are there any slices remaining?
For some people, pizza can be like a starter at a restaurant, not meant to get their stomachs full. They need to eat more slices than the rest of the sharers in order to be satisfied. So, after having had their share, they will always believe that some slices, two or three probably remained in parcel uneaten. So, to ask for the leftovers:
You may say:
Is there any pizza leftover?
or
That pizza was delicious. Are there any slices remaining?
ピザでお腹一杯にする食べ方をしないという点で、レストランでの前菜のようにみなしている人もいます。その場合お腹一杯になるには程遠いほどの食べ残しがでます。各自が自分の分を食べたあとは残りが出ます。残り物について尋ねる場合は、
Is there any pizza leftover?
（残っているピザはありますか？）または
That pizza was delicious. Are there any slices remaining?
（すごく美味しいビザですね。何切れか残っていませんか？）
と言えます。
Leftovers would be the word we use to describe the food that someone doesn't eat after having a meal. We can ask if we, "can have your leftovers." and we can ask if, "can I eat them."
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