何か用？って英語でなんて言うの？

A simple "Hey, you were looking for me?" will work in a casual situation with familiar people but if you just change the "Hey" to "Hi+the person's name" it will sound more respectful. The changes from casual to polite are very subtle in the english language so be very careful. "You called for me?" can be also used in both casual and polite ocassions. As with "What's going on?" , this is a pretty casual expression and has a feeling of concern as if saying "What's wrong?" Maybe you heard your mom was looking for you and that makes you worried so when you find your mom you'd say "Hey mom, what's going on?" or mix it with the other phrases: "Hey mom, you were looking for me? What's going on?"

You wanted to speak with me?' and 'Hey, did you need something from me?' are both good ways to say this. Bob told me that you need me, what's up? - 'Bob' can be replaced with any name. Use this if you want to say you the person that told you the other person was looking for you is.

Any one of these expressions should be adequate for this situation.

Fun way of telling are person they were looking for you.

Hi, what is it? and Did you need something? are both casual ways to ask what do you want. You could use these questions with your family, friends or at work.

Depending on who you are speaking to depends on your expression. If it is a friend "did you want me?" is perfectly fine however you would not say this in a more formal setting. "Sorry you missed me, is everything ok?" is more formal as well as "Sorry you missed me, how can I help you?

The first two options would be used in a more formal setting while "Looking for me?" is rather casual.

Any one of these expressions should be suitable for this situation. I hope this helps Fumiya :-)

The polite way is to simply reaffirm that they were looking for you. You can start with that question "Were you looking for me?". That asks the person if they were looking for you. If you are fairly sure they were looking for you than you can be more direct. "You needed me?" or "you needed something" gets more to the point and they should start explaining quickly what they needed you for.

speaking formally you could say either "I was told that you needed me for something?" or "did you want to speak with me?" or if you want to be more casual you could say "you need me?"

When someone is looking for you they could ask others that they know frequently communicate with you in an attempt to find you. When you are told that someone is looking for you, you can find the person looking for you and ask them any of the above questions. How can I help you? Asks the person if they need your help or assistance with something. Did you ask for me? Asks if you were called by the person. "Hi John, Sue tells me you were looking for me, how can I help you?" "Hi John, I heard you were looking for me, is it about your appointment later today?"

This would be a simple way of telling the person you was told they was looking for you and asking is everything ok.

If you say: How can I help? This is a polite way of asking why the person wants to find you. If you say: Who is looking for me? or Why do you want me? This is a more assertive way of asking the questions.

"What's up?" Is a casual and commonly used phrase, this is used when you'd ask someone 'whats wrong','what did you want/need'. "What did you need?" Is more of a direct question, implying that you, yourself were needed for something.