II. TEACHING GRAMMAR
It is a fact that while teaching tenses we teach grammar of the language in question. Ur (1996) defines grammar as “the way words are put together to make correct sentences (p.75)”. Radford (1998) characterises grammar as the study of the principles which govern the formation and interpretation of words, phrases and sentences. To Crystal (1992) Grammar is a systematic analysis of a language (p.158). It has also been known that grammar is traditionally divided into morphology and syntax.
We can say that grammar is abstract in the mind and it becomes concrete in the use. That is to say, it is something that is somewhere in the brain and turns out to be concrete in using. Moreover, it is the study of grammatical competence which means tacitly knowing about the grammar of a language. To introduce a technical term, we might say that native speakers have grammatical competence in their native language; by this we mean that they have tacit knowledge of their language. In other words, they are aware of how to form and interpret words, phrases and sentences in the language. So human beings have no conscious awareness of the psychological processes involved in speaking and understanding a language.
In a word, a grammar of a language is a model of the competence of fluent speaker of the language, and competence is reflected in intuitions about grammaticality and interpretation. A grammar of a given language is descriptive adequate if it correctly describes whether any given string of words in a language is or isn't grammatical, and also correctly describes what interpretations the relevant string has (Radford, 1997).
III. PROBLEMS IN TEACHING TENSES
Tense is a matter of inflection that is the changing of the shape of a verb by adding or not adding a morpheme. It should be borne in mind that "tense" and "time” are not to be regarded as synonymous in English. The term "tense" is used to refer to a verb form, not to chronological time (Graver, 1986, p.50). English verbs are used to express the aspect (simple, continuous or perfect) of an action or event. To some linguists, structurally speaking, there are two main tenses; present and past. Future is included in the present. On the other hand, most of the linguists state that there are three tenses in English; present, past and future. There are some problems arising in the learning of the use of these forms because of the first language interference and existing distinctions in a different way.
The choice of verb form (simple, continuous, perfect) made by English speaker depends on many factors, and not on a rigid set of grammatical rules. For the foreign language learner it seems to be quite difficult to be able to use the language appropriately for the appropriate situations. As they haven‟t developed on the stressed points efficiently they fail to get the message across. Now, let's examine some of the tenses causing difficulties for learners to learn through the results obtained from the research.