N3 — outside your level filter
or — puts a second alternative to the listener, between two questions
コーヒーにする？それとも、紅茶がいい？
koohii ni suru? soretomo, koucha ga ii?
Shall we make it coffee? Or would you rather have tea? casual
打ち合わせは今日でしたっけ。それとも、明日でしたっけ。
uchiawase wa kyou deshita kke. soretomo, ashita deshita kke.
Was the meeting today? Or was it tomorrow? neutral
それとも
それともsoretomoN3neutral