🛑 elder, eldest vs.

older, oldest 🛑
🔶 We ONLY use the adjectives elder and eldest before a noun (as attributive adjectives), and usually when talking about people / relationships within a family (within a familial context):
✅ Let me introduce Siga. She’s my elder sister.
❌Not: … She’s my sister. She’s elder.
✅ It’s Catherine’s eightieth birthday on Thursday. She is the eldest member of the family.
🔶 We also use elder and eldest as nouns:
✅ Jack is the eldest of four brothers.
🔶 Older and oldest are used in similar ways:
✅ My older sister is coming to stay with us at the weekend.
✅ Matt is the oldest of our children and Simon is the youngest.
🔶 Older and oldest can be used to refer to the age of THINGS more generally. Elder and oldest are not used to refer to the age of things:
✅ The town hall is by far the oldest building in the whole region.
❌ The town hall is by far the eldest building …
🔶 We can use older and oldest after a linking verb (as predicative adjectives):
✅ I think her grandfather must be older than her grandmother.
❌ I think her grandfather must be elder than …
To sum up:
❌ He is elder than me.
✅ He is older than me.
❌ He is the eldest man in the village.
✅ He is the oldest man in the village.
Elder and eldest can be used to talk about the order of birth of the members of a family. NOTE that they are only used before nouns. After a verb, we normally use older or oldest:
✅ My elder/older brother is a writer.
✅ His eldest/oldest son is in the Army.
✅ He is older than me.
❌ He is elder than me.
Elder and eldest can’t be used in the predicative position (after a verb).