おはようございます → “Good morning“. The very basic yet important one. Use this to everyone you see and walk into work.

よろしくお願いします →　”Thank you in advance“, “I look forward to working with you“, “Please fulfill or take care of my request”. The meaning of this phrase usually varies depending on the situation.

先に失礼します →　 “Sorry for leaving before you” or “I’m leaving now”. You can use it before leaving your work especially when you leave ahead of your other colleagues.

お疲れ様です →　”Thank you for your hard work“. This is the most contextual phrase used together with 先に失礼します →　”I’m leaving now”. This can also be used as a conversation starter and greetings.

すみません、今お時間大丈夫ですか？　→　”Excuse me, is now a good time“?. Usually use before starting a conversation with some who is busy or doing something.

~をもらっても良いですか？　→　”Please take a look at~” or “Can you take a look at ~~ for me“?. A polite way to ask someone to look at something to confirm you are doing it correctly.

申し訳ございません　→　”I am terribly sorry for~~“. This phrase is not just simply apologizing but also taking full responsibility for what is gone wrong.

ご迷惑をおかけして申し訳ありません　→　”I am sorry for the trouble” or “I am sorry for bothering you“. Usually, use if you happen to bring inconvenience to someone.

行ってまいります　→　”I’m going” or “I’m leaving“. This is different from 先に失礼します. This is used when you are going out of the office and more likely to return.

ただ今戻りました　→　”I’m back“. This is a polite way to say that you have come back after going outside.