imo this app is only useful for introducing vocabulary to yourself. For actual usage, you shouldn't hesitate to look for online resources through Google. You should also do these exercise on your own pace and proceed only when you're ready. Rushing through lessons for streaks doesn't help because the words won't stick.
Anyone looking for a good app Japanese language course try "Human Japanese". I have been using it for a while now and find it the most useful of any other app I've tried. It does a great job of explaining things. And, it works well with this Duolingo app too ( covers similar material in a similar order).
There are people who say '行ってきます' when go out their company. (the case s/he come back the company.)
A: 'I am going to Duo company. I will back two hours later. '
Yes, '失礼します' is used when s/he return home.
eg. When the end of the work tim
'失礼します' is used when s/he goes in or out the room as well.
eg. knock knock
A: 'どうぞ/Please enter the room. '
B: '失礼します' B goes into the room.
It is absolutry not necessary. Depends on the situation.
There are two verbs here, 行く、いく, "go" and 来る、くる, "come". The literal translation is something like "I will go and come back."
This expression uses what is called the "te form", or て形、てけい, which is a certain conjugation that has several uses, but very commonly serves as a conjunction that means "and". Here, 行く is conjugated as 行って, which serves to join it with 来る, thus "go and come".
I'm a huge fan of lingodeer app myself, as the audio files seem to be a bit better than most apps and the techniques used to teach languages have a more multifaceted approach than the one-trick pony that most apps are.
I like Duolingo mostly for how well it lends itself to impulse use --like waiting in line at a store or commercial breaks on the television. Also, it's probably the best of the completely free apps for languages in my opinion. Everybody else has some of their content locked up behind their pay wall--although hitting that pay wall takes longer and some apps than it does in others.
I started with YesJapan and their Japamese from zero books series. It teaches you literally from scratch. Great books written by a well respected Japanese interpiter, if your having a hard time I sugest you look into the company, or find the interpiter on youtube (channel name is Learn Japanese From Zero), this app is more of a practice or refresher for me after reading the books. Their first book is completely free but only if you view it on their website, dont worry it has print outs to teach you how to write the characters ans the sounds they make, sentence construction the whole bit. www.yesjapan.com the first book alone taught me just about 50% of what this app teaches. Hope this can help you in some way, this app really is only for people with an understanding already somce it doesnt really teach grammer or sentence structure that well or at all.
You're not alone. The only reason I've gotten as far as I have is because I'd had done some very casual learning independent of the app prior to trying it in duolingo. It's worth noting that until recently, Japanese was not a "fully released" language; it lacked a component on the desktop site. If you tried other language courses, you found the desktop versions included a LOT of discussion and extra information that the Japanese course lacked until just very recently. I was shocked when I learned how much more info the desktop page gives versus what we see if we only use the phone apps.
Edit: Looks like the Japanese desktop site is finally live, and it includes some extra information that the apps lack, just like other languages. Give it a try, lman582011!