

エレベーターで上に行きましょう。
机の上にかぎがありますよ。
テレビの上に何もありません。
"うえに(上に)" is in the lesson "Directions" (Level 19), along with 12 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.