

O Rui pediu uma bica e eu idem.
— Hoje estou cheio de sono. — Idem, dormi muito mal.
A Inês chumbou no exame e a irmã, idem.
"idem" is in the lesson "Adverbs 4" (Level 37), along with 11 other useful words. LinDuo has 180 topic lessons like this one, 2,380 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.