時間的に利用制限がありましたら、これは英語で「time-limit」に相当します。
「Limit」というのは「制限」です。
「90分の利用制限」は英語で「There is a 90 minute time-limit」になります。
本屋: bookstore
読み放題: read as much as you like; read as much as you want
人気: popular
スタバ: Starbucks
「本屋の本が読み放題の人気のスタバがありますが、90分の利用制限がありました。」は英語になりますと「You can read as many books as you want at the popular Starbucks, but there is a 90 minute time-limit.」になります。
英語頑張って下さい！
Some stores don't let people stay for as long as they want, especially stores that are very crowded with people. There must be a limit to the amount of time customers can stay. The amount of time you can stay in the store is limited or restricted. The amount of time can vary too. There can be a 30 minute time restriction to customer consumption. The amount of time a customer is allowed to stay in the store/cafe/restaurant is limited to 1 hour. The client can only consume for no longer than 90 minutes. This is often due to over crowding, popularity or any high demand for that place.
特に人気のお店では、お客さんが利用できる時間を制限しているところがあります。お客さんの利用できる時間を制限しなければなりません。
The amount of time you can stay in the store is limited/restricted.
（店を利用できる時間が制限されています）
利用できる時間もさまざまです。30分の利用制限がある場合もあります。
The amount of time a customer is allowed to stay in the store/cafe/restaurant is limited to 1 hour.
（お客さんが店/カフェ/レストランを利用できるのは1時間までです）
The client can only consume for no longer than 90 minutes.
（お客さんが利用できるのは90分までです）
これは大抵、お店の人気だったり、混雑していることが理由です。
At the popular Starbucks franchise, they usually monitor the duration of your stay.
Monitor = to check
Duration = how long something is done for
Saying Starbucks franchise also indicates the level of knowledge that you have of the company.
The language that i have shown in this instance would best suit someone who is speaking to a person who should be respected or in a formal manner.
At some busy Starbucks the store has a policy on how long customers can actually stay for.
When a company or store has a 'policy' in place, this means that the store has rules that they follow. In the case of Starbucks this rule is most probably in place to keep the flow of sales and customers moving and so that people do not spend hours talking over one coffee when they are taking up a table. Some customers may disagree with this policy and not like it. The 'policy' will not be in place at all stores, but only the very busy ones. 'Policy' can be used in a range of ways to, for example - "It is company policy that staff do not use mobile phones whilst on duty."
お店や会社にポリシーがあるということは、お店や会社には守らなくてはならない規則があるということです。
スタバの場合、おそらく、売り上げとお客さんの流れをスムーズにするためにテーブルで会話しながらコーヒーを飲める時間制限を設けているのでしょう。お客さんの中には、このポリシーに賛同しない人もいると思います。通常、このようなポリシーは忙しいお店に限ります。
”Policy"（ポリシー）は広範囲で使えます。例えば、”It is company policy that staff do not use mobile phones whilst on duty."（会社のポリシー上、仕事中にスタッフが携帯電話を使用することは禁止されています。）
Some Starbucks cafes may restrict how long you can spend inside
If your time (or other factor) is limited by regulation or common usage then it is said that 'there is a restriction' in place.
The verb is 'to restrict.'
'There is an age restriction at the bar. You must be 18 to buy alcohol.'
規則や慣例によって時間などが制限されている場合、「there is a restriction（制限がある）」と言えます。
その動詞は「restrict」です。
'There is an age restriction at the bar. You must be 18 to buy alcohol.'
（バーには年齢制限があります。お酒を買うには18歳以上でないといけません）
Some Starbucks stores limit the time a person spends in the shop.
Certain Starbucks stores have a time limit for how long you can stay.
Some of the most popular Starbucks place a time-limit on customers on how long they can be in the shop
When talking about how some of the most popular Starbucks have a time limit for how long you can stay, then you can say it in the following ways:
-Some Starbucks stores limit the time a person spends in the shop.
-Some Starbucks stores limit the time a person spends in the shop.
-Some of the most popular Starbucks place a time-limit on customers on how long they can be in the shop
人気のスターバックスでは利用時間に制限があることがあると伝える言い方です：
【例文】
-Some Starbucks stores limit the time a person spends in the shop.
［訳］利用時間に制限があるスタバもあります。
-Some Starbucks stores limit the time a person spends in the shop.
［訳］利用時間に制限があるスタバもあります。
-Some of the most popular Starbucks place a time-limit on customers on how long they can be in the shop
［訳］人気のスタバでは利用時間に制限があることもあります。
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