Greetings
Everyone seems to know "hello" in Japanese - konnichi-wa こんにちは. Even so, it is probably the most commonly misspelt word of all. Carefully look at the spelling in rōmaji and in hiragana. There is an extra ん and a particle "wa" (は).
The following YouTube should cover most of the important greetings. If you would like to know more or simply ask a question about it, contact me.
いらっしゃいませ！
irasshaimase!
Don't be scared by this sudden and loud greeting when you enter a shop. Similarly, don't feel obliged to respond - I bet you will say "thanks" anyway.
This is said by employees in shops, restaurants etc. as you enter their premises. It does not have a direct English translation but treat it as a "welcome to our shop".
Essentials
I made a non-negotiable deal with myself to learn the basic words for manners for each European country I travelled through. That would be the yes, no, please, thank you, excuse me, hello and goodbye.
In Japanese, there are numerous ways to say each (just like English) but the standard translations are listed below.
From my own personal experience, I think the most useful word to learn is すみません sumimasen. It not only means "excuse me" if you accidentally bump someone, want to pass people or want to give a brief apology. It is also the word you would call out in a restaurant to ask for assistance. It would be followed quickly by a はい hai from an employee scurrying over to wherever you are - service is brilliant in Japan, if not the most impressive memory of tourists visiting the country.
A more unique usage of すみません sumimasen is when a meal is brought to your table and placed in front of you. You would say sumimasen as the meal is placed down, meaning something close to "I appreciate the trouble you went to bringing it to me / making it".
