Je was op zoek naar: infinitiva (Spaans - Engels)

“must” es un verbo modal, por lo tanto no tiene forma infinitiva.
“must” is a modal verb, therefore it does not have an infinitive form.

registro llano\\nsustantivo£«frase preposicional\\nsustantivo£«a frase infinitiva\\n
plain register\\nnoun£«preposition phrase\\nnoun£«to infinitival phrase\\n

modo infinitivo
infinitive