Yes, "part-owner" is hyphenated when used as a compound noun to describe someone who owns part of something. The hyphen helps clarify that "part" modifies "owner." However, if used as a descriptive phrase (e.g., "She is a part owner of the business"), it can be written without the hyphen.
It is not hyphenated.
Motorcycle is not hyphenated
No it's not hyphenated.
words are only hyphenated when they have a separate meaning when separated than they do when hyphenated
Yes it should be hyphenated.
No, "hardworking" is not hyphenated.
It can be. Some words can be seen both hyphenated and non-hyphenated.
No. Well above is not hyphenated.
peace of mind is not hyphenated.
No, "homework" shouldn't be hyphenated.
Yes it should be hyphenated.
No they shouldn't be hyphenated.