In a situation where there is imminent danger of some kind, it is normal to first shout a warning such as 'Careful!!' or 'Watch out!' This may be followed by details of the danger: '....someone will get hurt! Children tend to get caught up in the excitement of the moment and often are unaware of possible dangers around them.
危険が差し迫った状況では、通常、"Careful!"（気を付けて！）または"Watch out!"（危ない！気を付けて！）と大声で注意します。その後、何が危険なのか具体的にフォローすることもあります。
例えば―
"Someone will get hurt!"（誰かがケガするよ！）
子供達がはしゃいでいる時は周りが見えなくなってしまう傾向があり、身の回りの危険を見落としてしまうことは多々ありますよね。
There are so many people here. Don’t wander around.
It’s crowded here. Don’t run.
There are so many people here. Don’t wander around.
【訳】ここにはたくさんの人がいるよ。うろうろしないで。
It’s crowded here. Don’t run.
【訳】ここは人がいっぱいだよ。走らないで。
どちらにするかはお好みだと思います。
wander aroundはうろうろするのがメインですので、走ってなくてもいいです。
don’t runは「走ってはダメ」と言っています。
crowded は「混んでいる」状態を言います。最初の文が簡単なので子供に言うにはいいかもしれませんが、これを機にこの単語を教えるという手もあります。
If your out with your child and they want to run around both of these answers may help to calm your child down.
"There'll be tears if you run about" - This answer is forewarning your child that if they do run around they will more than likely hurt themselves or someone else.
外出中にお子さんが走り回るようであれば、このような表現を使ってお子さんを落ち着かせることが出来るかもしれません。
例：There'll be tears if you run about.
（走り回ったら、泣くことになるよ。）
こちらの文章は、走り回ることで自分または他の人がケガをしてしまう可能性があるから気を付けなさい、とお子さんを嗜める表現です。
There isn't any room for running here, please stop else you might bump into someone.
No running, you might get hurt!
Kids are always on the move!
Crowded places are no fun when you have a child with you.
Running around in crowded places can get many people angry because you risk bumping into them, they might fall or drop whatever they might be holding.
To let your child know to stop running, use the sentences above.
"Sally, running in crowded places is not safe, you could bump into someone."
Crowded: full
Bump into: hit into something
子どもはいつも元気いっぱいです！
混み合った場所に子どもと一緒に行くのは大変ですね。
人混みを走り回ると他の人にぶつかって相手が転んでしまったり物を落としてしまったりということが起こります。怒ってしまう人もいるでしょう。
子どもに走るのをやめるように言うなら、上記の文が使えます。
"Sally, running in crowded places is not safe, you could bump into someone."
（サリー、人混みで走ると人にぶつかって危ない）
Crowded: 混雑した
Bump into: ぶつかる
Don't run around. You're going to bump into someone.
Don't run around because you are going to hit someone
When you want to tell your child to stop running because they might bump into someone, then you may communicate this in the following ways:
-Don't run around. You're going to bump into someone.
-Don't run around because you are going to hit someone
他の人にぶつかるので走り回らないよう子どもに伝えたいなら、次のように言えます。
-Don't run around. You're going to bump into someone.（走り回っては駄目。ぶつかるよ）
-Don't run around because you are going to hit someone（ぶつかるから走り回っては駄目）
"Stop running you might run into someone"
This sentence, often directed at kids who are playing and running around in a crowded environment, to ask the child/children to stop running as they might run into someone.
"Careful! you'll hit someone"
This is a more casual and short expression, to emphasis the point of stop doing what they're doing, to shout 'careful' is to imply that the chill will need to stop what they're doing and be careful, to avoid potential danger, harm or a mishap.
"Stop running you might run into someone"（走っちゃ駄目だよ。他の人にぶつかるかもしれない）
これは、混み合った場所で遊んで走り回っている子どもに対してよく言います。「人にぶつかるかもしれないから走っちゃ駄目」という意味です。
"Careful! you'll hit someone"（気を付けて、人にぶつかるよ）
これはよりカジュアルで短い表現です。相手が今していることについて「やめなさい」と伝えます。大声で子どもに 'careful' と言うと、「やめなさい」「気を付けなさい」のニュアンスになります。
Please don't run around, you might bump into someone and get hurt.
I need you to sit still please. It's so crowded here, you'll hit someone if you run around.
Be careful, instead of running around why don't you sit down and have a milkshake with mommy.
It's always polite to say "please" when asking someone to do something.
"Bump into someone" is another way of saying "hit someone."
"why don't you sit down and have a milkshake with mommy" - by saying this you are
suggesting an alternative fun activity that the child can focus on
instead of running around in the crowd.
"Crowded" is a word used to describe a place were there are a lot of
people.
"Be careful" is usually said when you are about to issue a warning to someone.
人に何かを頼むときには、"please" を加えると丁寧です。
"bump into someone" は "hit someone"（ぶつかる）の別の言い方です。
"Why don't you sit down and have a milkshake with mommy?"（座ってママと一緒にミルクセーキを飲もう）
→ここでは子どもに別の楽しい遊びを提案しています。
"crowded" は混雑した場所を表します。
"Be careful" は普通「これから相手に警告をする」というときに使われます。
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