| Singular | Plural |
| attorney-general | attorneys-general |
| brother-in-law | brothers-in-law |
| bystander | bystanders |
| commander-in-chief | commanders-in-chief |
| court martial | courts martial |
| cupful | cupfuls |
| father-in-law | fathers-in-law |
| general staff | general staff |
| go-between | go-betweens |
| governor-general | governors-general |
| handful | handfuls |
| heir apparent | heirs apparent |
| maidservant | maidservants |
| man-of-war | men-of-war |
| mix-up | mix-ups |
| mother-in-law | mothers-in-law |
| mouthful | mouthfuls |
| notary public | notaries public |
| passer-by | passers-by |
| sergeant major | sergeants major |
| sister-in-law | sisters-in-law |
| son-in-law | sons-in-law |
| step-parent | step-parents |
| step-daughter | step-daughters |
| step-mother | step-mothers |
| tablespoonful | tablespoonfuls |
| takeoff | takeoffs |