These are some words and greetings that you can say without being embarrassed.
English word Romaji Japanese
Hi/Hello Konichiwa こんにちわ
How are you? Genki desuka? 元気ですか?
What are you doing? Nani shite iru no? 何しているの?
Slangs:
English Romagi Japanese
Um… Ano… あの。。
Stupid Aho あほ (used in kansai areas)
Idiot Baka ばか
I see Ah sou あぁ、そう (informal)
English word Romaji Japanese
Hi/Hello Konichiwa こんにちわ
How are you? Genki desuka? 元気ですか?
What are you doing? Nani shite iru no? 何しているの?
Slangs:
English Romagi Japanese
Um… Ano… あの。。
Stupid Aho あほ (used in kansai areas)
Idiot Baka ばか
I see Ah sou あぁ、そう (informal)