| 
 | Expression | Definition | Example | 
| 
 | sibling | brother or sister | I have three siblings. | 
| 
 | older / younger | senior or junior in age | I have one older brother, but I don’t have any sisters. | 
| 
 | a family of (number) | a way to say how many members in a family | We’re a family of four: mom, dad, my older sister, and myself. | 
| 
 | only child | a child without a brother or sister | Many of my friends have siblings, but I am an only child. 
 | 
| 
 | be part of ~ | is a member of … | I am part of the language exchange group. | 
| 
 | take care of… | to do the things that are needed to help or protect (someone) or to keep (something) in good condition | My mom takes care of my grandparents. | 
| 
 | grow up | to become an adult | Children grow up so quickly. | 
| 
 | (do) for a living | your work | John paints houses for a living. | 
| 
 | work as… | have an occupation as … | My friend works as an accountant. | 
| 
 | (someone) must be… | something is likely | Your parents must be very happy to have such a sweet daughter. |