The main difficulty in a document for text+translation is the requirement for two parallel text streams: one for the original language, one for the translation.
The most stringent constraint is parallel, i.e. when you consider pages, they alternate between the streams. There is presently no solution in Writer for this. When you reach bottom of page, a new page is allocated for the current stream. Thus you can’t automatically lay out two alternating parallel streams.
A second constraint is the necessity to have “synchronisation points” between the streams so that corresponding texts are not too far apart. These “sync points” can be paragraphs (assuming both languages have the same semantics for what they call a “paragraph”), or headings if they occur very frequently. Other possibilities can be considered.
Some may suggest to use linked frames, but this departs from Writer use case. You switch to desktop publishing (DTP) where pages are primary objects while Writer is flow-oriented (it allocates dynamically pages to accommodate text). With Writer in “DTP mode”, you must create yourself all pages, insert a text frame covering the whole print area (so that no stray text can be placed on the page) and link the frames from page to page. It can be done if the book is 10 pages long but this is a real pain for 100+ pages.
There is yet another problem if you want to collect a TOC. Entries in the TOC may not be in page order because frames are scanned in creation-time order.
A possible workaround if you require strictly parallel (separate) pages. You can lay out your streams inside a (single) page. To give more width to the streams, orient your page landscape.
Insert a 2-column table, allowing it and its rows to split across pages, one column for original language, the second for the translation.
The “sync points” are mentioned earlier are rows. You can tune the frequency of these “sync point” by the text you put in a cell. However, I recommend you stick to one paragraph. The main reason is to facilitate table splitting. Laying out huge cells (rows) has a considerable impact on performance (all the more on big tables spanning pages and pages). Using smaller cells offers more split/spill-over opportunities.
You can also limit tables to text between headings: you trade a huge table for several smaller (independent) ones which puts less stress on Writer.
With more information on your purpose, I can give better suggestions.
When asking here, always mention OS name, LO version and save format. The latter (.odt vs. docx) is the most important because “comfortable” formatting of sophisticated documents relies on styles which generally are lost when saving to DOCX.
Yes provided your document is methodically styled. Styles are organised according to a hierarchical inheritance tree. Style attributes can be “transparent” (in which case their value is inherited from the ancestor) or explicitly “set” (in which case they override what is inherited from the ancestor). Beware! I used word “set”, but I should have written “touched”. Suppose you select Fancy font to change from inherited Liberation Serif and you change your mind afterwards. If you select again Liberation Serif, you don’t revert to inherited value. You override this inheritance because you explicitly select the font. You must press Reset to Parent button to put all attributes in this screen to “transparent”.
All you have to do is to customise Default Paragraph Style which is the ultimate ancestor of all styles (and for this reason should not be used to format text; the “standard” style for your narrative is Body Text).
Factory configuration contains several intermediate styles which control (override) various branches in the tree. You access these intermediate styles in a simplified form with Tools>Options, LO Writer>Basic Fonts (Western).
