Fixing capital letters with Change case in Write by Zaweba
Format > Change case in Write by Zaweba switches text between sentence case, lowercase, UPPERCASE and more, and Shift+F3 cycles through them.

Typing a whole line with Caps Lock left on is one of those small accidents everyone makes. So is pasting a heading from a spreadsheet that shouts in capitals, or receiving a list of names typed entirely in lower case. Retyping is tedious and invites new mistakes. Change case in Write by Zaweba fixes the capitals for you.
The five options
Format > Change case offers five choices for the selected text.
Sentence case gives a capital at the start of each sentence and lower case for the rest. It is right for ordinary prose and for headings in a plain, modern style.
lowercase turns every letter small. It is a good first step when text arrives in a jumble of capitals, because you can then put back only the capitals you want.
UPPERCASE turns every letter into a capital. It suits short labels, the odd sign or a heading on a poster, though long passages in capitals are hard to read.
Capitalise Each Word puts a capital at the start of every word. That is the style many people use for titles and for names of places and organisations.
tOGGLE cASE swaps every letter, capitals to small and small to capitals. It exists for one job in particular: rescuing text typed with Caps Lock on by mistake, where the shift key gave you lower case at the start of words and capitals everywhere else.
Cycling with Shift+F3
Shift+F3 cycles through the options on the selected text. Press it once and look; press it again for the next style. For quick fixes it is faster than opening the menu, and you can stop as soon as the text looks right.
Select the text first. If you only want one word changed, double click it, then press Shift+F3 until it reads correctly.
Formatting stays put
Changing case keeps the character formatting of the text. Bold words stay bold, italic words stay italic, and colours and highlights stay where they were. You can fix the capitals in a formatted heading or a paragraph full of emphasis without having to reapply anything.
This also makes Change case different from the all caps effect, which is a kind of formatting. All caps shows letters as capitals while the text underneath is unchanged, so turning the effect off brings back the original. Change case actually rewrites the letters. Use the effect when capitals are a matter of style, such as a heading style that should always look upper case, and Change case when the letters themselves are wrong.
Where it helps most
Lists of names and addresses copied from forms are a common case. People fill in forms in all capitals or none, and a mailing list needs to look tidy before it goes into letters. Capitalise Each Word sorts most of them in one go. Afterwards, read through for names that don't follow the pattern, such as those with "Mc", "Mac" or an apostrophe, and fix those by hand.
Headings are another. If your document uses headings in sentence case but some were typed in title case, Change case brings them into line. Do it before building a table of contents, so the contents page matches.
Text pasted from older documents and emails often arrives in capitals for emphasis. Converting it to sentence case and then putting a single word in bold or italic usually reads better.
Keep an eye on acronyms and proper nouns after any change. Sentence case will lower the capitals in names like London or in short forms like UK, because it can't know which words are special. A quick read after the change catches them before anyone else does.