Looking up...
いっしょに映画を見に行きましょう
Let's go watch a movie together
Together, simultaneously, or in the company of someone
友達といっしょに勉強する
To study with friends
家族といっしょに旅行に行く
To go on a trip with family
Often used to indicate doing something with others, but can also mean 'at the same time' in some contexts.
'いっしょに' is more casual, while '一緒に' is more formal but both are commonly used.
'いっしょに' is often used to indicate doing something with someone else, not just at the same time.
From '一緒' (issho) meaning 'together' + 'に' (ni) indicating direction or accompaniment
'いっしょに' is a casual way to say 'together'. The more formal equivalent is '一緒に' (issho ni). Both are used interchangeably in most contexts.