"Roedd e'n arfer byw yn Iwerddon."

Translation: He used to live in Ireland.

[JamesTWils]

Doesn't "arfer" in this context usually mean "usually"?

[ibisc]

It can do. With the imperfect (roedd etc) the meaning 'used to' does not actually require arfer, although people often put it in:

• Roedd e'n byw yn y Rhyl - 'He was living in Rhyl', or 'He used to live in Rhyl'

[JamesTWils]

Ah, I was striving to use "usually," since Duolingo can often be quite literal, even when it is awkward in English ("I was usually living in Ireland"). I sometimes forget that the people writing the Welsh lessons are probably native speakers of English as well, or at least more native than I am in any language other than English.

[ibisc]

'Usually' is usually (sorry...) translated as fel arfer or fel rheol:

• Pan o'n i'n gweithio yn y Fenni'r llynedd, ro'n i'n aros mewn gwesty yn Llangatwg fel arfer. (When I was working in Abergavenny last year, I usually stayed in a hotel in Llangattock.)