I'm teaching students using MS Word and LaTeX.
So here the mechanism with word:
MS Word never had a good word spacing and you simply can not adjust it.
To get a better word spacing you have to add manual hyphenations or to
rephrase the text!
That means if you have no possibility to add an hyphenation to get larger word spacing you realy have to rephrase the sentence (in german not very often).
The culprit is that the hyphenation for german is not pretty, the english one is better. The best practice in MS Word is (for german!) to switch of the automatic hyphenation and add manual hyphenation signs already while writing words like
(I used here normal
- to show the added hyphenation signs).
That is only the first step. It makes the second step easier (after a while you will become very good in guessing where the hyphenation has to be ...)
After finishing your text inclusive all text/writing corrections you have to start at the begin of your document and check the layout of the lines, check if the hyphenations (if you are using automatic hyphenation that is very important!) and check the correct placing of images too. If you have lines to be to short or too long use manual hyphenation to help MS Word to get a better line layout (that is the only thing Word does for you in typographical view), if that does not help rephrase the sentence.
Do not the same error most of my students do at the beginning of the course to correct each line at once. You do not know if there will be an image disturbing the current layout or you have to make a correction of text later.
That is all fine tuning and had to be done at the end of the work after you are shure your text is fixed and will not change. And btw you will not loose such a lot time in constant correcting things which are at last no problem ...
BTW: If possible and you can write in LaTeX I would use LaTeX for books, reports etc. MS Word was written to do simple typewriting and not to create good typografy and that you can see today even with current versions of Word.
Good typography you get with LaTeX (academic work, books etc) or Adobe Indesign (used also for layouting books, magazines, newsletters etc).
But of course your professor has to accept that then too ...