ましょう => let's ~; shall we ~ N5
てしまう => Did something N4
Secondary Verb
ましょうか => shall I ~; used to offer help to the listener N5
~ ほうがましだ => better than; would rather ~ N1
Evaluate
ようか~まいか => whether or not; considering options N2
~ましょう。 => Let's (together), Shall I/we…? N5
Verb suffixes
何をしますか => What are you doing... N5
Doubt
てしまう => to do something by accident, to finish completely N4
~いはしまいか => whether or not; considering options N1
Base, base
てもよろしいでしょうか => May I... N4
Allow
いたします => to do (polite form of します) N4
でしょう/でしょうか => Is that right? ask a question in a polite way N5