How to get line breaks and translation clips to work?

Does anyone know where I can read more detailed information about editing a lesson? Specifically, I’m trying to figure out how to change the sentence markets and how to use the “clip” function. Often the system will split a line incorrectly if it sees a period. So, “Mr. Jones went to the store.” comes out as “Mr.” “Jones went to the store.” If I delete the end of sentence markers and save the file, they’re back in the wrong place when I open the file. The “clips” function looks like it would allow one to enter a translation for each line, but it only seems to read in translations from the system, a translation typed into a “clips” text box doesn’t show when a translation is requested in the line by line mode, only Google’s translation. Which may be how it is supposed to work, but I’d like to enter my own translations. Thanks.