How should one teach grammar?

Teaching GRAMMAR is not an easy task!  

One should teach grammar through a communicative task , with incidental focus on form. A focus on form overtly draws students' attention to linguistic elements as they arise incidentally in lessons whose overriding focus is on meaning or communication (Long, 1991: 45-460). This can be done through error correction, noticing of salient forms in texts, and teacher- or student-initiated attention to a language feature. Schmidt in Ur (2010) explained that noticing is necessary for learning the grammar of a language. There is now ample evidence that many learners are capable of mastering a wide range of explicit grammar rules. Green and Hecht (1992), for example, found that university-level students of English in Germany were able to produce clear explanations for 85% of the grammatical errors they were asked to explain, while overall the learners in their study (who included secondary school students) managed satisfactory explanations for 46% of the errors.

Macrory and Stone (2000) reported that British comprehensive school students had a fairly good explicit understanding of the perfect tense in French (e.g., they understood its function, they knew that some verbs used avoir and some être, they were familiar with the forms required by different pronouns, and they were aware of the need for a final accent on the past participle). Hu (2002) found that adult Chinese learners of English demonstrated correct metalinguistic knowledge of prototypical rules of six English structures (e.g., for the definite article specific reference constituted the prototypical rule) but were less clear about the peripheral rules for these structures (e.g., generic reference).He went on that awareness of grammatical rules, forms and meanings may facilitate later acquisition. This can be realized through occasional lessons where learners’ attention is drawn to forms, often in the shape of an explicit rule. Communicative tasks can be done also through discussion of examples, and some intellectual effort. In a communicative task, one may teach bits of grammar / vocabulary / spelling before, during or after: but the focus is always on the communicative task. After giving the tasks, the teacher as suggested by Ellis (1996) should : first, teach those forms that differ from the learners’ first language (L1), and second, teach marked rather than unmarked forms.

Given all these grounds, I believe that communicative task is appropriate in teaching grammar to learners.

Which is better between implicit and explicit teaching of vocabulary?

Explicit teaching of vocabulary is better than implicit teaching. In explicit teaching of vocabulary, the instructor clearly outlines what the learning goals are for the students, and offers clear, unambiguous explanations of the skills and information structures they are presenting whereas in implicit instruction, the instructor does not outline such goals or make such explanations overtly, but rather simply presents the information or problem to the student and allows the student to make their own conclusions and create their own conceptual structures and assimilate the information in the way that makes the most sense to them.

The claim that explicit teaching of vocabulary is better than implicit teaching is supported by a study conducted by Laurie Cutting and her team in Vanderbilt University, which found out that explicit teaching of vocabulary is effective than implicit teaching. The study examined 34 adult readers, from 21 to 36 years of age. The subjects were taught pseudowords—words that are similar to real words but that have no meaning, such as “skoat” or “chote.” Then, through both explicit and implicit instruction, subjects were taught meanings for these words. (In the study, both of these pseudowords were associated with the picture of a dog.)

The goal was to gain a clearer understanding of how people with different skills and capabilities processed short-term instruction, how effectively they learned, and how those differences looked physiologically in the brain.

In the end, the subjects were all able to learn the pseudowords. But, through functional magnetic resonance imaging (fMRI), the researchers learned that something deeper was actually taking place: subjects previously identified as excellent readers showed little difference between how they processed explicit vs. implicit instruction. Average readers, on the other hand, showed through their fMRIs that they had to work harder to learn through implicit instruction; for them, explicit instruction was the more effective method.

With these claims, I believe learners would best learn vocabularies through explicit teaching.