At what age do children start and finish elementary school in your country?
How old are kids when they start and finish grade school in your country?
At what age do children start and finish elementary school in your country?
「あなたの国では子供は何歳で小学校に行き始め、何歳で終えますか？」＝「小学校は何歳から何歳までですか？」
at what age で「何歳で」
「小学校」は elementary school
How old are kids when they start and finish grade school in your country?
「あなたの国では子供が小学校に行き始め終えるのは何歳ですか？」＝「小学校は何歳から何歳までですか？」
「小学校」は grade school という人もいます。
ご参考になれば幸いです！
When do kids start going to elementary school in your country? And when do they finish?
How are you when you start elementary school and what age do you finish?
From when to when do you start and finish elementary school?
"When do kids start going to elementary school in your country? And when do they finish?" Even though you don't specify that you're talking about age in the question, the person would understand that you meant age.
"How are you when you start elementary school and what age do you finish?" When you use "you" in the sentence people understand that you're asking about children in general and not the person themselves.
"From when to when do you start and finish elementary school?" This is a very informal way of asking someone. "from when to when" let's the person know you're asking about an age range, instead of only one age.
"When do kids start going to elementary school in your country? And when do they finish?"（あなたの国では子どもは何歳から小学校に通い始めますか。そして卒業するのは何歳ですか）
→「年齢」とは言っていませんが、年齢の意味だと伝わります。
"How are you when you start elementary school and what age do you finish?"（小学校には何歳で入学し何歳で卒業しますか）
→この文の "you" は、「あなた」ではなく、一般的な「子ども」を指します。
"From when to when do you start and finish elementary school?"（小学校には何歳で入学し何歳で卒業しますか）
→これは非常にインフォーマルな言い方です。"from when to when" は、一つの年齢ではなく年齢幅を尋ねます。
At what age to you start and finish school in your country?
If you are asking someone what age they were when they personally started or finished school you can ask:
-"How old were you when you started school?"
-"How old were you when you finished school?"
If you wish to know more of the general ages that children start and finish school in another country you can ask:
-"What age do you start and finish school in you country?"
-"How old are your children when they first attend school?"
-"How old are the kids when they graduate from high school?"
You can say 'finish school' or 'graduate from school'. They mean the same thing, though 'graduate from school' is more commonly used.
その人が小学校に入学あるいは卒業したときに何歳だったか確認するなら、次のように言えます。
-"How old were you when you started school?"（あなたは小学校に入学したとき何歳でしたか）
-"How old were you when you finished school?"（あなたは小学校に卒業したとき何歳でしたか）
その国で一般的に何歳で小学校に入学し卒業するのか確認したいなら次のように言えます。
-"What age do you start and finish school in you country?"（あなたの国では何歳で小学校に入学し卒業しますか）
-"How old are your children when they first attend school?"（あなたの国では何歳で小学校に入学しますか）
-"How old are the kids when they graduate from high school?"（高校は何歳で卒業しますか）
'finish school'（卒業する）と 'graduate from school' は同じ意味です。どちらも使えますが、'graduate from school' の方が一般的です。
How old are children when they start and finish elementary school in your country?
"Children" is the plural form of child which is irregular. Elementary school is also called "primary school" in some countries. I hope that this helps! :)
What's the elementary school starting and finishing age for children in your country?
At what age do children in your country need to register for elementary school and when do they finish?
The phrase 'starting age' used in the first question means the age when children have to 'register' and begin elementary school. The phrase 'finishing age' means the age at which the children complete elementary school and become eligible to progress to the next level. The age at which they finish elementary school marks the end of their elementary school years and it is a period between the year they started and the year they finished. This should be the same for every child unless something happened to the child during the period, such as getting seriously sick and not being able to attend school in a certain year.
So, you may ask your audience as follows:
What are the elementary school starting and finishing ages for children in your country?
or
At what age do children in your country need to register for elementary school and when do they finish?
一つ目の例で使われている 'starting age' は子どもが小学校に入学する年齢を指します。
'finishing age' は子どもが小学校を修了し上級学校に進学できる年齢を指します。
小学校に入学しそして卒業する年齢というのは、病気などで学校に通えなかった期間がない限り皆同じです。
次のように聞けます。
What are the elementary school starting and finishing ages for children in your country?
（あなたの国では小学校は何歳から何歳までですか）
At what age do children in your country need to register for elementary school and when do they finish?
（あなたの国では小学校に何歳で入学し何歳で卒業しますか）
At what age do students usually start and finish primary school?
How old are you when you start and finish primary school?
At what age do students usually start and finish primary school? - you can use the question "at what age...?" to ask how old a person is when they do something. Primary school is another way of saying elementary school.
How old are you when you start and finish primary school? - you can ask in second person to ask in general how old a person is when they do something by asking "how old are you when...".
At what age do students usually start and finish primary school?（小学校は普通何歳から何歳まで行きますか）
→何かをするときの年齢を尋ねるときには、"at what age...?" が使えます。"primary school" は "elementary school"（小学校）の別の言い方です。
How old are you when you start and finish primary school?（小学校は普通何歳から何歳まで行きますか）
→"how old are you when..." で何かをする一般的な年齢を尋ねることができます。この 'you' は一般的な「人」を指します。
How old are children when they start and finish elementary school in your country?
おっしゃられている内容は、1つには、以下のようにも表現できると思いました(*^_^*)
How old are children when they start and finish elementary school in your country?
「直訳： あなたの国では、子供が小学校に入る時と終える時は、子供は何歳ですか？」
これで、
「何歳で小学校に入り、何歳で小学校を出るのか」を尋ねることが出来ます。
以上です。
少しでも参考になれば幸いです(*^_^*)
The entrance age for elementary school varies, but usually it goes from 6 years old...to 12 years old
The starting point or entry / exit for elementary education varies from country to country...However it usually runs from around 6 years old up to 12 years old.
We say I started school at... such and such an age...I finished elementary school at...
The entrance age for elementary school varies, but usually it goes from about 6 years old...to around 12 years old
小学校に入学する年齢、卒業する年齢は国によって異なりますが、普通は6歳から12歳くらいまでです。
次のように言います。
I started school at...（...歳のときに就学しました）
I finished elementary school at...（...歳のときに小学校を卒業しました）
The entrance age for elementary school varies, but usually it goes from about 6 years old...to around 12 years old
（小学校に入学する年齢はさまざまですが、たいていは6歳から12歳くらいまでです）
日本 
アメリカ合衆国 
南アフリカ 
イギリス 
