1. A 'mate' is just another word for a friend, used mainly in British and Australian English. It can combine with other words to mean various different things. Here are the commonest combinations: A flatmate = someone who lives in the same flat as you. A workmate = someone who works in the same place as you A classmate = someone who studied in the same class as you 2. Your aunt is your father or mother's sister. Your great-aunt is your grandfather's or grandmother's sister. In other words, they are different generations. An aunt is of your parents' generation, whereas your great-aunt is of your grandparents' generation. An aunt doesn't have to be a blood relative - you also call your uncle's wife your 'aunt'. 3. Sister-in-law (meaning 1) = your brother's wife Sister-in-law (meaning 2) = your wife's sister/your husband's sister Half-sister = This is someone with whom you share one parent. For example, let's say that your parents get divorced. Your father marries again and has a child with his new wife. That child is your half-sister or half-brother, meaning that you have the same father but a different mothers. Your father's new wife is your 'stepmother', and if she brings with her a daughter from her first marriage, that daughter is your 'step-sister'. I hope that all makes sense.

Hello Asem, A 'mate' is informal language for a friend whereas a 'flatmate' is someone you share a flat with. An 'aunt ' is your mother's or father's sister, whereas a 'great aunt' is the sister of one of your grandparents. (Note we often tell young children to call family friends 'Aunt' and 'Uncle' too.) Your 'sister-in-law' is your sister by marriage so it is the sister of your husband/wife. (The same goes for all the in-laws.) If your parents get divorced/separate and the one you are living with gets married again to a person with a daughter from a previous relationship, this is your step-sister. A half-sister has one of your parents the same as you and one different. If in the previous example, your parent and their new partner have a child together, that will be your half-sister or half-brother. Hope this helps Bob

Mate - a friend, someone you like to hang out with. Flatmate - a roommate, someone you live with. Not necessarily a friend, but could be a friend. Aunt - the sister of one of your parents. Great-aunt - one of your parents' aunts; the sister of one of your grandparents. Sister-in-law - a woman married to one of your siblings; the wife of your brother or sister. Half-sister - you share one parent with this woman, but not both. So you have the same dad, but different moms. Or the opposite. Step-sister - your mom and her dad got married, but you are not related to this girl by blood. (Or any other parent combination; one of your parents and one of her parents married each other, so legally she is your sister.)