Family is one of the very first topics that comes up in almost any English conversation, and yet many B1-C1 learners still rely on a narrow set of basic words (mother, father, brother, sister) when English actually has a rich, precise vocabulary for family relationships. This guide covers the full range, from immediate family through to the words native speakers use for step-family, in-laws, and describing relationships naturally.
2. Immediate Family
Word
Meaning
parent
a mother or father
sibling
a brother or sister
only child
someone with no brothers or sisters
twins
two children born at the same time to the same mother
only child / eldest / youngest
position among siblings: no siblings / oldest / youngest
guardian
a person legally responsible for a child who isn't their parent
3. Extended Family
Word
Meaning
grandparent / grandchild
your parent's parent / your child's child
great-grandparent
your grandparent's parent
aunt / uncle
your parent's sister / brother
cousin
the child of your aunt or uncle
niece / nephew
your sibling's daughter / son
relative
any member of your family, general term
extended family
relatives beyond parents and siblings, such as grandparents, aunts, uncles and cousins
💡
Cousin doesn't change with gender
Unlike "niece/nephew" or "aunt/uncle," English uses "cousin" for both male and female relatives: "my cousin John" and "my cousin Sarah" both use the same word, no separate male/female form.
4. In-Laws & Step-Family
Word
Meaning
mother-in-law / father-in-law
your spouse's mother / father
brother-in-law / sister-in-law
your spouse's sibling, or your sibling's spouse
stepmother / stepfather
your parent's new spouse, not your biological parent
stepbrother / stepsister
the child of your stepparent, not your biological sibling
half-brother / half-sister
a sibling who shares only one biological parent with you
in-laws
your spouse's family collectively
⚠️
Step- vs Half- vs In-Law
These three prefixes are easily confused. "Step-" means a relationship formed through remarriage (no blood relation). "Half-" means sharing exactly one biological parent. "In-law" means related through marriage, not blood. Mixing these up is a very common vocabulary error.
5. Relationship Status
Word
Meaning
single
not married, not in a relationship
in a relationship
dating someone, not necessarily married
engaged
having agreed to marry, before the wedding
married / divorced / widowed
the three main marital status categories beyond single
partner
a neutral term for a spouse or long-term significant other, regardless of marital status
fiancé / fiancée
a man / woman you are engaged to
6. Family Life — Useful Phrases
Phrase
Meaning
to take after someone
to resemble a family member (in looks or personality)
to run in the family
to be a trait shared by many family members across generations
to grow up
to develop from childhood into adulthood
to raise a child
to care for and bring up a child
to be close to someone
to have a strong, warm relationship with a family member
to fall out with someone
to have an argument that damages a relationship
a close-knit family
a family with strong, close relationships
7. Common Mistakes
❌ Incorrect
✅ Correct
Why
My cousin brother
My cousin
English doesn't distinguish "cousin brother/sister" the way some other languages do, just "cousin."
My mother-in-law's family
My in-laws
"In-laws" already refers to your spouse's family collectively, no need for "mother-in-law's family."
He is my half brother because we have different parents.
He is my stepbrother, because we have different parents entirely.
"Half-brother" specifically means sharing ONE biological parent, not zero.
I have two brother.
I have two brothers.
Plural nouns need the -s ending, a basic but very common slip under pressure.
8. Exercises
A. Gap Fill — Complete correctly (8 questions)
1. My father's brother is my ___.
2. My sister's daughter is my ___.
3. My parent's parent is my ___.
4. I have no brothers or sisters, I'm an ___ child.
5. My husband's mother is my ___.
6. My mother remarried, so I have a ___.
7. "He looks just like his father" means he ___ after his father.
8. A family where relationships are very strong is a ___ family.
1. Your sister's son is your... (a) nephew (b) cousin
2. Your spouse's sister is your... (a) sister-in-law (b) stepsister
3. A child with no siblings is an... (a) only child (b) single child
4. Sharing one biological parent makes you... (a) half-siblings (b) stepsiblings
5. "To resemble a relative" means to... (a) take after them (b) fall out with them
Show Answers (B)
1.a 2.a 3.a 4.a 5.a
C. Error Correction (3 questions)
1. My cousin brother lives in Spain.
2. He is my half brother because we have completely different parents.
3. I have two brother and one sister.
Show Answers (C)
1. My cousin lives in Spain. 2. He is my stepbrother, because we have completely different parents. 3. I have two brothers and one sister.
D. Freer Practice — Write Your Own Sentences (2 tasks)
1. Describe your own immediate family in 2-3 sentences, using at least three vocabulary words from this page.
2. Write a sentence using "take after" or "run in the family."
Show Answers (D)
Model answers will vary. Examples: 1. "I have one older sister and one younger brother. My parents have been married for 25 years." 2. "My love of music runs in the family, my grandmother was a pianist too."
9. Mini Quiz
10. Exam Focus — Cambridge, IELTS, SELT
Exam
How This Is Tested
Sample Question
Cambridge B1 Preliminary / B2 First
Family vocabulary is core content in Speaking Part 1 and Reading dialogues.
"Can you tell me about your family?" in the Speaking interview.
IELTS Speaking
Family is one of the most common Part 1 topics, examiners expect precise, natural vocabulary.
"Do you have a large family?" "Are you close to your extended family?"
Trinity GESE/ISE (SELT)
Family is one of the very first, most predictable topics in the SELT interview.
"Tell me about your family." "Who do you live with?"
11. Frequently Asked Questions
"Sibling" specifically means a brother or sister; "relative" is a general term for any family member, including cousins, aunts, uncles and grandparents.
"Step-" means related through a parent's remarriage, no blood relation. "Half-" means sharing exactly one biological parent. "In-law" means related through your own marriage, not blood.
No — English uses "cousin" for both, unlike "niece/nephew" or "aunt/uncle," which do have separate male and female forms.
To resemble a family member, in appearance or personality: "She takes after her mother," meaning she looks or acts like her mother.
"We're a close-knit family" or "I'm very close to my parents" are both natural, commonly used phrases.
Yes — family is one of the very first and most predictable topics in the SELT interview, at every level.
Reading a vocabulary list takes you part of the way. Real fluency comes from using these words in conversation, with a tutor who corrects you immediately. Book a free level test with Elite Language Solutions and find out exactly where you are.