dudar (en + inf)
verbCEFR B2
What does “dudar (en + inf)” mean in English?
to hesitate to do something
to hesitate to do something (no dudar en + inf — formal invitation formula; dudar en = to be reluctant to)
Example sentences
No dude en ponerse en contacto con nosotros si necesita cualquier aclaración adicional.
Do not hesitate to contact us if you need any further clarification.
Si necesita asistencia adicional, no duden en llamar a nuestro servicio de atención al cliente.
If you need further assistance, do not hesitate to call our customer service team.
Dudó unos segundos antes de intervenir, pero finalmente se animó a plantear su pregunta.
He hesitated for a few seconds before speaking up, but finally plucked up the courage to ask his question.
How to use it
No dudar en + infinitive is a fixed formal courtesy formula meaning 'do not hesitate to + inf'. It is ubiquitous in formal correspondence and service-language contexts: 'No dude en contactarnos' / 'No duden en hacer cualquier consulta'. The positive dudar en + inf means 'to hesitate to do' (without the negation): 'Dudó en llamar' = he hesitated to call. The negated formula is a B2 fixed expression that signals service register. Register note: the equivalent informal formula is si tienes cualquier duda, dímelo.
Common mistake
The positive dudar en (to hesitate) and the fixed negative no dudar en (do not hesitate) trigger opposite meanings — don't confuse them. English speakers sometimes reconstruct the formula incorrectly as *'no hesitar' — hesitar is not the natural Spanish verb here. Also, the formula is no dude en (not *no dude de): dudar en = to hesitate to, dudar de = to doubt / be sceptical of.