doubtful [ˈdaʊtfʊl] adjective 1. [unlikely] poco probabile 2. [uncertain] incerto ( f incerta) to be doubtful about or of sthg non essere sicuro ( f sicura) di qc 3. [dubious] dubbio ( f dubbia)
Complétez la séquence avec la proposition qui convient. I'm tired because I … all morning. have been working have working