Many are listed in most dictionaries; those that are not, such as half- smile, can be hyphenated, except that in some cases half is an adverb–The fault is half mine; He was half dead–and other conventions apply. Also, when half is a kinship term it does not take a hyphen: half brother.

Do you hyphenate half sister?

For instance, hyphens appear in some family terms (like “brother-in-law”) but not in others (“half sister”). In fact, “half” is all over the map as part of a compound: sometimes hyphenated (“half-moon,” “half-life”), sometimes separate (“half note,” “half shell”), and sometimes solid (“halfhearted,” “halftime”).

Can you say half brother?

A half-brother is someone who shares only one parent with you; either his mother or his father is your biological parent as well. Hence the term half-brother. A stepbrother, on the other hand, has no blood connection with either of your biological parents.