Important Swahili

• jambo -- hello
• habari? -- how are you?
• mzuri -- good/fine
• mzuri sana -- very good/fine
• asante -- thank you
• asante sana -- thank you very much
• kwaheri -- goodbye
• mzungu -- white person
• wazungu -- white people
• nyama -- meat
• nyama ngombe -- beef
• mboga -- vegetables
• duka la dawa -- pharmacy

Slang:

• mambo vipi? -- How are you?
• poa -- fine/good/cool
• poa k'chisi -- excellent / cool bananas! (literally "cool, like a crazy man")
• salaam alekum -- hello (only in Zanzibar)
• alekum salaam -- hello (response, also only in Zanzibar)
• mzungu chisi -- "crazy white man".  This is a good, self-deprecating thing to say whenever you want to get a laugh out of someone!

Maasai

• supai -- hello (to male)
• epa -- hello (response to supai)
• tarkenya -- hello (to female)
• ecco -- hello (response to tarkenya)
• siddai -- good (all purpose response)  This is a good all-purpose word to use to any question that you don't understand.