Complementació verbal:
explain

THAT/WHAT + SUBORDINADA: 1) She explained that there were many factors to take into account.
Va explicar que hi havia molts factors a tenir en compte.; 2) He explained what his company does.
Explicava el que fa la seva empresa.
INTERROGATIU + SUBORDINADA: The police refused to explain how they had uncovered the evidence.
La policia es va negar a explicar com havien descobert l'evidència.