

いっしょに晩ご飯を食べませんか。
週末、友達といっしょに映画を見ました。
ねえ、いっしょに帰ろう。
"いっしょに" is in the lesson "Adverbs 4" (Level 37), 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.