Japanese learning

いっしょに〜しませんか? 〜しましょうか。

1) いっしょに〜しませんか?(Shimasen ka?) = wouldn’t you do (something) with me

2) 〜しましょうか。(shimashou!) = Let’s do (something)

 

They are very similar but ~Shimasenka has a more polite nuance and difficult for people to answer “No”.  はなみをしませんか? Wouldn’t you do Hanami with me?