Questions & Answers about Við tölum um aldurinn hans.
- Við = we
- tölum = (we) talk / are talking – present tense, 1st person plural of tala “to speak, to talk”
- um = about (also “around”, “over”, etc. in other contexts, but here = about)
- aldurinn = the age (from aldur “age” + -inn definite article “the”)
- hans = his (non‑reflexive masculine possessive pronoun)
So the whole sentence is literally: We talk about the age his, which in natural English is: We talk about his age.
Aldurinn has the definite article attached as a suffix:
- aldur = age
- aldurinn = the age
In Icelandic, the definite article is usually added to the end of the noun (and often to an accompanying adjective), not as a separate word like “the” in English. So:
- aldur – age
- aldurinn – the age
In this sentence, aldurinn sounds like you are talking about a specific, known age (his age in this situation), rather than age in general. English translates both as “his age”, but Icelandic shows the specificity with -inn.