A quick funny story. Details in a language are so important. I am in a class right now called Second Language and Culture Acquisition - (SLACA) the goal of which, among other things is to learn how to acquire a second language by developing a language learning strategy. My partner, fellow LBT candidate Kory Fay, and I are learning Swahili with a native speaker of Swahili from Kenya in East Africa. For our 'final exam' for the language learning we are simulating a trip to the market where we go and find what we need and bargain for and pay for it. So we were learning some stuff about that the other day and I piped up, "So if I want to say 'Do you have fish', do I say "Ou ko samaki?" And my language helper just started cracking up and laughing so hard and she said, "You are so close, but what you actually said was, 'Pardon me, miss. Are you a fish?' The correct way to ask if she has fish for sale is "Ou ko na samaki." Now 'na' seems like a pretty small thing and when you're speaking Swahili at regular speed you hardly notice it's there. But it makes all the difference between calling someone a fish or seeing if she has fish for sale. Good to know. Now I'm famous in the SLACA class for my Swahili skills, which is always fun. 
Kuaheri na Bwana sa fiwe! (Goodbye and Praise the Lord!)
Rich