

明日はどこで会いましょうか。
そのかばんはどこで買いましたか。
昨日、どこで晩ご飯を食べた?
"どこで" is in the lesson "Adverbs 3" (Level 35), along with 11 other useful words. LinDuo has 180 topic lessons like this one, 2,379 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.