This study investigates the errors commonly made by Vietnamese learners of English in the acquisition and use of ditransitive verbs and their complements. While ditransitive verbs play a central role in English syntax by allowing two objects, their syntactic and semantic patterns diverge significantly from those in Vietnamese. Such divergences often lead to systematic errors in sentence construction, particularly in the ordering of direct and indirect objects, the use of prepositions, the identification of object types, and the distinction between complements and adjuncts. Drawing on a combination of contrastive analysis and error analysis, this research identifies five major error types: (1) misordering of complements, (2) misuse or omission of prepositions, (3) misidentification of object types, (4) confusion between finite WH-interrogative clauses and nominal relative clauses, and (5) difficulties in distinguishing between ditransitive verbs and complex transitive verbs. The findings highlight the influence of first language transfer from Vietnamese, where object positions are relatively flexible and prepositions function differently. The study concludes with pedagogical recommendations aimed at reducing errors and enhancing learners’ syntactic competence. It is hoped that the results will contribute not only to improving teaching strategies but also to refining translation and grammar instruction for Vietnamese learners of English.