Select all that apply. Which sentences have correctly formed question tags?
The trainees understood, didn't they?✓Respuesta correcta
Everything is labelled, aren't they?
Let's review the map, shall we?✓Respuesta correcta
Nothing was missing, was it?✓Respuesta correcta
Explicación
The correct tags reverse polarity, match the available auxiliary, and use the suitable pronoun or fixed special form. The faulty example treats everything as plural even though its standard tag pronoun is it.