It could be looked at the arguments for and against incorporating grammar into language teaching, and concluded that, on balance, there is convincing case for a role for grammar.
The E-Factor: Efficiency = economy, ease, and efficacy.
Given that dealing with grammar is only a part of a teachers’ activities, and given that classroom time is very limited, it would seem imperative that whatever grammar teaching is done as efficiently as possible. If, as has been suggested, the teachers; energies should be at least partly directed at getting learners to communicate, prolonged attention to grammar is difficult to justify. Likewise, if a grammar activity requires a great deal of time to set up or a lot of materials, is it the most efficient deployment of the teachers’ limited time, energy and resources? When, considering an activity for the presentation or practice of grammar the first question to ask, is: “How efficient is it?” Efficiency, in turn, can be broken down into three factors: economy, ease, and efficacy.
When presenting grammar a sound rule of thumb is: the shorter the better. It has been shown that economy is a key factor in the training of technical skills: when learning how to drive a car or operate a computer, a little prior teaching seems to be more effective than a lot. The more the instructor piles on instructions, the more confused the trainee is likely to become. The same would be apply in language teaching: be economical.
Be economical, too, in terms of planning and resources. The ease factor recognises the fact that most teachers lead busy lives, have many classes, and simply cannot afford to sacrifice valuable free time preparing elaborate classroom materials. Of course, investment of time and energy in the preparation of materials is often accompanied by a commitment on the part of the teacher to making them work. But, realistically, painstaking preparation is not always going to be possible. Generally speaking, the easier an activity is to set up, the better it is.
Finally, and most importantly: will it work? That is to say, what is its efficacy? This factor is the least easy to evaluate. We have to operate more on hunch than on hard data. Learning, like language, resists measurement. Of course, there are tests, and these can provide feedback to the teacher on the efficacy of the teaching/learning process. Nevertheless, testing is notoriously problematic . Moreover, there is much greater skepticism nowadays as to the extent that teaching causes learning. This need not undermine our faith in the classroom as a good place for language learning. We now know a lot more about what constitute the best conditions for learning. If teachers can not directly cause learning, they can at least provide the optimal conditions for it. 
The prerequisite for learning is attention. So the efficacy of a grammar activity can be partly measured by the degree of attention it arouses. This means trying to exclude from the focus of the focus of the learners’ attention any distracting or irrelevant details. Attention without understanding, however, is probably a waste of time, so efficacy will in part depend on the amount and quality of contextual information, explanation and checking. Finally, understanding without memory would seem to be ineffective, and so efficacy of a presentation will also depend on how memorable it is.
None of these conditions, however, will be sufficient if there is a lack of motivation, and in the absence of some external motivational factor (for example, an examination, or the anticipation of opportunities to use the language), and it is the teachers’ job to choose tasks and materials that engage the learners. Tasks and materials that are involving, that are relevant to their needs, that have an achievable outcome, and that have an element of challenge while providing the necessary support, are more likely to be motivating than those that do not have these qualities.
Efficiency, then, can be defined as the optimal setting of three related factors: economy, ease, and efficacy. To put it simply: are the time and resources spent on preparing and executing a grammar task justified in terms of its probable learning outcome?
The A-factor: Appropriacy
No class of learners is the same; not only are their needs, interests, level and goals going to vary, but their beliefs, attitudes and values will be different too. Thus, an activity that works for one group of learners – that fulfils the E-factor criteria – is not necessarily going to work for another. It may simply not be appropriate. Hence, any classroom activity must be evaluated not only according to criteria of efficiency, but also of appropriacy. Factors to consider when determining appropriacy include:
1) The age of the learners;
2) Their level;
3) The size of the group;
4) The construction of the group;
5) What their needs are;
6) The learners interests;
7) The available materials and resources;
8) The learners’ previous learning experience and hence present expectation;
9) Any cultural factors that might affect attitudes, their perception of the role and status of the teacher;
10) The educational context, private school or state school, at home or abroad.
Activities that fail to take the above factors into account are unlikely to work. The age of the learners is very important. Research suggests that children are more disposed to language learning activities that incline towards acquisition rather than towards learning. That is, they are better at picking up language implicitly, rather than learning it is a system of explicit rules. Adults learners, on the other hand, may to better at activities which involve analysis and memorization.
Cultural factors, too, will determine the success of classroom activities. Recently there have been a number of writers who have queried the appropriacy of indiscriminately and uncritically applying methodologies in contexts for which they were never designed. Communicative Language Teaching has been a particular target of these criticisms. Communicative Language Teaching values, among other things, learner-centredness, that is, giving the learners more responsibility and involvement in the learning process. This is often achieved through discovery learning activities (for example, where learners work out rules themselves) and through group work as opposed to the teacher-fronted lesson. Communicative Language Teaching also takes a relatively relaxed attitude towards accuracy, in the belief that meaning takes precedence over form. Finally, Communicative Language Teaching has inherited the humanist view that language is an expression of personal meaning, rather than an expression of a common culture.
Of course, no learning situation is static, and, with the right combination of consultation, negotiation, and learner training, even the most entrenched attitudes are susceptible to change. The teacher is therefore encourage to be both adventurous as well as critical. 
So, the second chapter of this work dealt with the reasons why grammar is important, why the grammar is needed to be learnt. It was referred to the factors which will ensure the quality of the lesson of grammar, also, attitude of scientists to grammar today.