The particle に followed by は. Emphasizes or topicalizes the element marked by に (location, time, target, etc.).
部屋には誰もいなかった。
There was nobody in the room.
この駅にはエレベーターがない。
This station doesn't have an elevator.
朝9時には学校に来てください。
Please be at school by 9 a.m.
Used in phrases meaning "in order to / for the purpose of" (e.g., 'to do X, (you need) ...'). Indicates purpose or necessary condition.
日本語を上手に話すには練習が必要だ。
To speak Japanese well, you need practice.
免許を取るには試験に合格しなければならない。
To get a license, you have to pass the exam.
本を借りるにはカードが必要です。
You need a card to borrow books.
Used as 'as for / regarding' (topic marker after に); can show respect toward the subject or set up contrast about the referenced item.
先生にはいつもお世話になっています。
I am always indebted to my teacher.
この問題には専門家の意見が必要だ。
This issue requires expert opinion.
彼にはわからないかもしれないが、私には重要だ。
He may not understand, but it's important to me.
Used to acknowledge a point about A (Aには〜が) and then introduce a contrast or reservation ("admittedly A is..., but..."). Emphasizes the repeated element before contrasting it.
値段には安いには安いが、品質が心配だ。
It's true the price is cheap, but I'm worried about the quality.
彼には若いには若いが、経験が足りない。
He is young, admittedly, but lacks experience.