It is not possible add hyphenated words (e.g. “nitty-gritty” in English) as one word on Language Reactor as it misidentifies them as two separate words and forces you to add them as two words (possibly due to the word boundaries being determined by a regex that discriminates punctuation). This issue persists even if I try to use the text feature to add the words manually.
While this may be fine for some languages (like English), for languages with affixes that take on different meanings from word to word and can form completely different words (like Tagalog) that may attach them with hyphens or would otherwise benefit from having hyphenated words recognised as one word, this bug is rather detrimental to the learning experience.
I am using LR to learn Filipino (Tagalog) > English in Singapore, and the video that this bug can be seen in is here, for the word “pag-uusapan” (Tagalog adds a hyphen or a space after prefixes that end in consonants if the following word starts with a vowel).
As a fix, I suggest either allowing the user to configure for each language if they would prefer to add hyphenated words as one or multiple words, having a system to determine if a hyphenated compound should be treated as a word or separate words (like polling a dictionary API), allowing the user to choose whether to add a hyphenated word as one word or separate words each time they come across one.