Spanish phrase
Sin duda.
Meaning
Without a doubt.
When to use it
Emphatic confirmation of a fact or promise. Functions as a forceful yes or reassurance in both casual and formal contexts, friendly but definite.
Example dialogue
Sin duda iré a la reunión mañana.
Without a doubt, I'll go to the meeting tomorrow.
Perfecto, te esperamos a las 10.
Perfect, we'll expect you at 10.