sister-in-law
B1Neutral to formal
Definition
Meaning
The sister of one's spouse, or the wife of one's sibling.
A female relative by marriage, specifically through a spouse or sibling. In some contexts, can refer to the wife of one's spouse's sibling (i.e., co-sister-in-law).
Linguistics
Semantic Notes
A compound noun with a plural form 'sisters-in-law' (head pluralization). Denotes a kinship relation established through marriage, not blood.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning. Both use the same term. Spelling of related words may differ (e.g., 'honour' at a wedding in UK vs. 'honor' in US).
Connotations
Neutral in both varieties. No regional connotations.
Frequency
Equally common in both varieties.
Vocabulary
Collocations
Grammar
Valency Patterns
[possessive pronoun] + sister-in-lawsister-in-law + [of + possessive pronoun]sister-in-law + [to + person]Vocabulary
Synonyms
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “My sister-in-law from another mother (humorous, for a very close friend treated as family).”
Usage
Context Usage
Business
Rare. Might appear in HR forms for emergency contacts or family leave policies.
Academic
Used in anthropology, sociology, or legal texts discussing kinship systems.
Everyday
Common in family discussions, introductions, social events, and storytelling.
Technical
Used in legal documents (wills, deeds) to specify familial relationships.
Examples
By Part of Speech
verb
British English
- She was sister-in-lawed into the family last summer.
- I am being sister-in-lawed by my brother's upcoming marriage.
American English
- He got sister-in-lawed when his sister married.
- They are sister-in-lawing her into all the family traditions.
adverb
British English
- She behaved sister-in-law-ly throughout the ordeal.
- He supported her very sister-in-law-ly.
American English
- She acted sister-in-law-like during the crisis.
- He treated her sister-in-law-ishly.
adjective
British English
- We have a strong sister-in-law bond.
- The sister-in-law relationship can be complicated.
American English
- She offered sister-in-law advice on the matter.
- They attended a sister-in-law brunch.
Examples
By CEFR Level
- My sister-in-law is very kind.
- I have one sister-in-law.
- Her sister-in-law lives in London.
- My brother and his wife are visiting; I get on well with my sister-in-law.
- She became my sister-in-law after the wedding last year.
- I often go shopping with my sister-in-law.
- Despite being my sister-in-law for only two years, we have developed a remarkably close friendship.
- The legal document required me to list all siblings and sisters-in-law.
- Her relationship with her sister-in-law was strained due to family politics.
- The anthropologist noted that the role of the sister-in-law in that patrilocal society was one of both support and potential tension.
- In her memoir, she poignantly describes navigating the complex dynamics with her new sister-in-law, who was also her former university rival.
Learning
Memory Aids
Mnemonic
Think: She is a sister because of the 'law' of marriage, not the law of blood.
Conceptual Metaphor
MARRIAGE CREATES A NEW FAMILY TREE (The in-law is a branch grafted onto the family tree through marriage).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not translate as 'свекровь' (husband's mother) or 'золовка' (husband's sister). The Russian language often uses more specific terms (невестка, свояченица) depending on the exact relation, which English combines under 'sister-in-law'.
Common Mistakes
- Using 'sister-in-laws' as the plural (incorrect; correct is 'sisters-in-law').
- Confusing it with 'step-sister' (related by parent's remarriage, not by one's own marriage or sibling's marriage).
Practice
Quiz
What is the correct plural form of 'sister-in-law'?
FAQ
Frequently Asked Questions
No. It has two main meanings: 1) the sister of your spouse, and 2) the wife of your sibling (brother or sister).
A sister-in-law is related by marriage (through your spouse or your sibling's spouse). A step-sister is related through the remarriage of a parent (you share no biological parents).
Typically by her first name. There is no special title like 'Aunt' for this relationship. Formality depends on family custom and personal preference.
Yes, the term applies regardless of the genders involved. The definition is based on the marital relationship, not the gender of the individuals.