Verb + de someone or something
se tromper
deno preposition
The constructions
dese tromper de quelque chose
Meaning : to get the wrong one
Je me suis trompé de bus.
Do not writeJe me suis trompé le bus.
no prepositionse tromper
Meaning : to be mistaken
Tout le monde peut se tromper.
Why
Se tromper de, with no article after de, names the thing mixed up: se tromper de porte, de numéro, de jour. Without an object, se tromper means to make a mistake. Tromper quelqu'un, non-pronominal, means to deceive them.
The trap for a Chinese speaker
搭錯車、走錯門: Chinese builds the error into the verb. French says se tromper DE bus, se tromper DE porte, with de and no article.