Breakdown of Завтра мы идём в ресторан.
мы
we
ресторан
restaurant
в
in / to (direction)
идти
to go (on foot) / to proceed, go (of a process)
Questions & Answers about Завтра мы идём в ресторан.
How does завтра work here? It means "tomorrow", but the verb идём is in the present tense.
Just like in English, Russian can use the present tense to talk about fixed plans in the near future. Because we have the time word завтра (tomorrow), it is clear that мы идём means "we are going" tomorrow rather than right now.
Why use идём instead of another Russian word for "to go"?
идём is a form of the verb идти, which means "to go on foot" or "to go" to a local place. It is used when making a single, specific trip. If you were taking a plane or train to another city, you would need a different verb for going by vehicle.
Why is it в ресторан? Doesn't the word ресторан change form when there is motion toward it?
We are using в (to/into) to show direction, which requires the accusative case. However, ресторан is a masculine inanimate noun (not a living person or animal), and in the accusative case, masculine inanimate nouns look exactly the same as their basic dictionary form.
Does the word order matter? Could I put завтра at the end of the sentence?
Yes, you absolutely can say Мы идём в ресторан завтра. Russian word order is very flexible. Putting Завтра at the very beginning just puts a little extra emphasis on when the plan is happening, setting the scene right away.