At its core, foreigners learning Vietnamese is an activity of second language acquisition

Speaking of language acquisition, it is clear that with a second language, how quickly or slowly learners take it in depends on a great many factors. Therefore, scientific theories are the basis for improving and raising the effectiveness of teaching and learning a second language.

The process of acquiring a second language differs in many ways from that of the first language. The first language is taken in very easily because it is instilled into the mind through an environment of communication in the native tongue, with no prior imprint of any other language, so no conflicts, impositions or changes arise. Therefore, the learning environment is highly valued when one starts learning a foreign language, because it is both the purpose and the condition for cultivating practical language skills. For the most part, second language acquisition runs into obstacles because of a lack of an environment for communicating in the second language. This reality is an important pointer for building exercises that train foreign students to use Vietnamese sentences. The exercise system must bring in communicative contexts and communicative situations that are authentic, vivid and familiar, closely following the study, daily life and everyday social activities of foreign students studying in Vietnam. The value of the exercise system is raised considerably as a result, avoiding theoretical drills that are detached from reality. According to Dr. Vu Lan Huong, “the process of teaching foreign languages should follow the model of real communication in everyday life (speech/spoken language); the more closely communicative situations in study resemble communicative situations in real life, the more easily the speaking skills formed in learners transfer from the classroom to life outside”. This conclusion led us to the idea of building an exercise system in which, beyond the school environment, sentence exercises are set in other environments such as amusement parks, markets, supermarkets, bookshops, hospitals, and other administrative offices such as embassies, study-abroad offices, and so on, turning each practice exercise into an opportunity for students to practise expressing, presenting, asking, answering and showing emotions in Vietnamese sentences that are correct both semantically and grammatically. In particular, the hardest part of second language acquisition is using the second language like a native speaker. To achieve this, the sentence exercise system must take care to create materials rich in the culture of communication, with the habits of thought and speech of Vietnamese people.

Furthermore, Krashen, an expert in second language acquisition research, holds that “people acquire foreign languages in a natural order”: learners of a second language acquire grammatical structures in a predictable order. Therefore, input knowledge and interaction are two processes that learners carry out at the same time when doing sentence exercises. This is the key when designing a curriculum, because second language acquisition requires the teacher’s support in providing knowledge and in detecting and correcting errors. Krashen also stresses that output, the practice of producing utterances in speech and in writing, is even more important than input knowledge. What he emphasises means that social communication through listening, speaking, reading and writing, just like the situations and contexts that occur in everyday life, is the basic foundation for developing the rules of language. From practice, students draw out the rules of sentence grammar and the types of sentences with equivalent meaning, so that they can flexibly vary sentence types and make them diverse and rich. To further support the view on the importance of creating a system of exercises that trains the skill of using Vietnamese sentences for communicative purposes, we cite the opinion of Dr. Vu Lan Huong: “Grammar, therefore, should be the grammar of speech, realised in conversations/situations, based on authentic materials and directing the reader towards specific communicative purposes”. And from the perspective of foreign experts on practising sentence use in teaching and learning a second language, Ellis set out 10 principles, including the following: “Instruction needs to ensure that learners develop both a rich repertoire of formulaic expressions and a rule-based competence; Instruction needs to ensure that learners focus predominantly on meaning (semantic meaning, i.e., the meanings of lexical items or of specific grammatical structures, and pragmatic meaning, i.e., the highly contextualized meanings that arise in acts of communication); Successful instructed language learning also requires opportunities for output; In assessing learners’ L2 proficiency it is important to examine free as well as controlled production”. In acquiring a second language, beyond the importance of vocabulary, which any foreign language learner acknowledges, communicative grammar truly needs attention because it is the part that enables speakers and writers to express an idea completely. Accordingly, sentence exercises based on the communicative approach are built on the orientation of teaching communicative grammar to foreign language learners.

Thus, second language acquisition requires learners to understand and process specific grammatical structures when receiving input material and producing utterances when carrying out tasks. Through receiving and producing sentences, students at the same time memorise grammatical structures in the context of the task they have just carried out.