Practice: family and relatives
What you will be able to do
Name any relative age-first, address your partner's parents correctly on a first visit, and answer the standard family questions without stalling on the word for brother.
Age comes first (พี่/น้อง), then sex (ชาย/สาว); above the parent the sex is marked (ลุง/ป้า), below it the side (น้า/อา); grandparents mark the side (ปู่/ย่า/ตา/ยาย). Address in-laws as คุณพ่อ/คุณแม่.
Thai names relatives in this order…
Thai names relatives age first, then side, then sex. That's why there's no word for just “brother” — you settle older or younger first.
There is no Thai word for just “brother”. How do you build it?
There is no word that means brother and nothing else. Build it the Thai way: older or younger first (พี่/น้อง), then add ชาย or สาว only if the sex matters. พี่ชาย said about a man younger than you is simply the wrong fact.
น้า (náa) is…
น้า (náa) is your mother's younger sibling, of either sex. Below the parent the axes swap: the side is marked and the sex is not. Don't assume น้า means auntie.
ลุง (lung) is…
ลุง (lung) is the elder brother of your mother or father. Above the parent, the side is not marked and the sex is — one word covers both sides.
ปู่, ย่า, ตา, ยาย — which is your mother's father?
ตา (dtaa) is your mother's father. ปู่ is father's father, ย่า father's mother, ยาย mother's mother. Inside a Thai family the side is marked every time in this generation.
หลาน (lǎan) means…
หลาน (lǎan) is one word for grandchild, niece and nephew — it marks neither generation nor sex. If you need to know which, ask.
To your partner's mother's face, you say…
To their faces the words are คุณพ่อ and คุณแม่ from the first meeting, until the family moves you down to plain พ่อ and แม่. Wait to be moved. แม่ยาย is for describing the relationship, not addressing.
ผัว and เมีย — the rule is…
ผัว/เมีย have not become neutral. A foreigner using them about somebody else's husband or wife sounds coarse. สามี and ภรรยา cost you nothing, and at a counter they are the accepted answer.
พ่อเสียแล้ว — why เสีย, not ตาย?
เสีย (sǐa) is the gentle “passed away”; ตาย (dtaai) is blunt about people. It needs no apology in your voice and gets none in the reply.
The polite address for an older relative is…
คุณ in front of any older kinship word softens it: คุณตา, คุณยาย, คุณลุง, คุณป้า.
ลูก (lûuk) means…
ลูก (lûuk) is a child of somebody, at any age — not the same as เด็ก (dèk), a child by age. A man of fifty is still his mother's ลูก.
ผมเป็นลูกเขย means…
ลูกเขย (lûuk-khǒei) is a daughter's husband — son-in-law. Useful at a village event where nobody has placed you yet.
Asking whether two people are siblings or cousins, you say…
เป็นพี่น้องกันหรือลูกพี่ลูกน้องกัน (bpen phîi-náwng gan rěu lûuk-phîi-lûuk-náwng gan) — are you siblings or cousins? The question that stops you building a tree from an English sentence.
ลูกคนโต means…
ลูกคนโต (lûuk khon dtoo) — the eldest child. Worth having ready, because the eldest is expected to support the parents. ลูกคนกลาง middle, ลูกคนเล็ก youngest, ลูกคนเดียว only child.
Common mistake
Translating brother and sister straight across — there is no Thai word for just “brother”. And the aunt/uncle words: ลุง/ป้า don't tell you the side, น้า/อา don't tell you the sex. Build the sentence the Thai way round: age first.