contrast.deber-deber-de
Deber vs deber de: must (duty) vs must (guess)
Deber + infinitive = obligation (debes llegar a las ocho); deber de + infinitive = probability (debe de estar durmiendo). Speech blurs it; writing shouldn't.
⚠ Stub: AI-drafted outline, not yet reviewed. The structure is permanent; the content will be expanded.
contrastB2stubdraftv0.1.0
Explanation
The norm assigns duty to the bare verb and inference to deber de: debe pagar (he must pay — obligation) vs debe de ganar bien (he must earn well — guess).
Real usage drops the de constantly, so context decides; but producing the distinction marks careful Spanish. The negative inference: no debe de saber ('he probably doesn't know').
Examples
Los socios deben firmar ambos.
Both partners must sign.
Both partners must sign.
Region: global
No contesta; debe de estar en el avión.
He's not answering; he must be on the plane.
He's not answering; he must be on the plane.
Region: global