If you are doing the course on iOS or Android, you cannot currently access the Tips through the app. To access the Tips, you will have to access the course using a web browser at https://www.duolingo.com/. You can still do it on your mobile device, but you will have to use the web browser instead of the app (or you can do it from a computer). When you click on a Skill, it will expand to reveal a Start button and a Tips button.
Some learners translate Klingon to English simply by translating from the end of a sentence to the beginning, rather than understanding Klingon word order.
So we are fairly strict about word order in places such as A B je, which means “A and B”.
The meaning may be similar or often identical to “B and A”, but the writer may have meant something by putting A first, and this is another reason we insist on the correct word order.
In English the apostrophe is just thought of as a grammatical mark and so it can seem unimportant. However, in Klingon the apostrophe is used to mark a full letter of the alphabet which is called qaghwI'. Leaving the qaghwI' off of a word is just the same as leaving any other letter off of the word. Sometimes Duolingo can be lenient on single letter errors and sometimes it is strict. It has to do with algorithms in the software that I haven't figured out how to predict well. But it is, in fact, wrong to leave the qaghwI' out of a word, so please pay special attention to it, whether the software marks you wrong or not.