This is an important lesson, because it's all about manners. Japanese spend a lot of time excusing themselves and thanking you, good manners are very important!
"Douzo" (doh-zoh) is a word you'll hear a lot in Japanese. It means "Please", but it is used when inviting someone to do something, like offering someone food or letting someone get ahead of you in line. It is not used to ask for things, for that, you'd say Kudasai (Kuo-da-sai). Of course, when someone offers you something, you should thank them. "Arigatou" (ah-ree-ga-toh) is the easiest way to say thank you, and it will do for most occasions. But say someone lets you have the last piece of sushi! A normal "arigatou" might not be enough to express your gratitude! So you can say "Doumo Arigatou!" (Doh-moh A-ree-ga-toh), that's sort of like "Thank you very much!" If someone saves you from a giant ninja crow-bot, you can show even more appreciation by saying "Doumo Arigatou Gozaimasu!" (Doh-moh A-ree-ga-toh Go-zah-ee-mas' :Remember those silent U's from our previous lessons!) So, what does a well mannered person do when someone says "Thank you"? You tell them "You're Welcome". You can do this with "Dou itashimashite". Yeah, I know that's a mouthful, but you can do it! "Doh Ee-tah-shee-mah-shee-teh" Practice a few times.... "Do' itashimashite" is really more like "It's nothing", or "No problem", etc, as you'll see. OK, ready to review?
Do'zo = Please (to offer)
Kudasai = Please (to ask for)
Arigato' = Thanks
Do'mo Arigato'! = Thank you very much!
Do'mo Arigato' Gozaimas'! = Thank you very much!!!
Do' itashimashite = You're welcome/it's nothing
Apologizing is also very important to show good manners. If you should inconvenience someone, it's expected that you should say Sumimasen (Sue-mee-mah-sen) "Excuse me". This applies even if the problem is not your fault as long as you're sorry that it happened. For something more serious, a more serious apology will be needed. Doumo sumimasen is more formal. Gomen Nasai (Go-men Nah-sai) "I'm sorry" is similar in use to "Sumimasen", but is usually used with people you are familiar with already. It's often shortened to just Gomen. When someone apologizes to you, you can respond with "Do' itashimashite" which you've already learned can be used like the English phrase "No problem". Or you can just say Iie (Ee-eh) "no", sort of like saying "No need to worry about it". (And since I'm teaching you "No", I may as well mention that Hai is "yes" in Japanese, but I bet you knew that one already.) Another thing you can say is Daijobu (Die-joe-boo) "No need to worry" or "it's all right". This is a very handy word, and it can be used like our "Okay". So lets review:
Sumimasen = Excuse me
Doumo sumimasen = Excuse me (more formal)
Gomen Nasai = I'm sorry
Gomen = Sorry
Hai = Yes
Iie = No
Daijobu = It's Okay
Got it? Practice those, and if you have some anime videos in Japanese to watch, try listening for some of the words you've learned. (It's a fun way to learn!)