Forma anómala de los espectros de fotoemisión:

Hirtle (2007) emphasized the category of tense as the common denominator for any description of the verb. Nevertheless, he mentioned there is little agreement among grammarians with regard to English verb tenses. As Klammer et al. (1995) asserted the first job in studying grammatical analysis is that the researcher should learn how forms are categorized. Thus, investigator will be able to classify new constructions and form which might be encountered. Concerning the tenses, some grammarians and linguists believe there are two kinds of tenses in English: present and past.

Jespersen, (1933) said, “The English verb has only two tenses proper, the present and the preterit” (p.231). H. Palmer, (1969) believed in two tenses regarding the time reference of English tenses. “Strictly speaking, English has only two tenses to cover the past- present- future time continuum” (p. 176). Greenbaum (1996) affirmed that there are two tense categories of present and past in English that are indicated by the forms of the verb.

In his view, for distinctions in time the verb phrases and auxiliary forms (for referring to future time) are used.

Some linguists like Zandvoort (1969), K. Allen (2006), made distinction between tenses and aspects in English. The problem is that tense and grammatical aspect has internal relation and they cannot be inseparable completely. Dahl (1985) noted, “The distinction between tenses and aspects is by no means clear, although everyone knows what the typical cases are like” (p.25).

Hornstein (1993) in his “neo-Reichenbachian” analysis of tense identified six basic tenses in English. The structures of which are given as following:

“S, R, E present, E, R–S past, S–R, E future, E–S, R present perfect, E–R–S past perfect, S–E–R future perfect.

[E= event time] , [S= moment of speech] , [R= relationship between E & E] ” (p. 15).

Enç (1987) rightly pointed out “Tense is usually said to be indexical, in that the truth of a tensed sentences is relative to the speech time (that is, to the context of utterances)”

(p.642). In Kilby’s opinion (1984), “Tense is a category which primarily involves the time of the event or state specified by the verb relative to the moment of utterance” (p.

15). He did not include future tense for English. “It is sometimes assumed that English has three tenses– past, present and future – but in fact there are only two relevant formal distinctions in English” (p. 16)

Cowper (2003) in the feature-geometric approach, in contrast with theories based on Reichanbach’s formula, argued the narrow tense system of English is not complicated. In this approach, the tense system consists [± past] plus Precedence as implanted with monovalent feature. By Precedence, she meant the finite past marker (often called –ed), and the past participle suffix (usually called –en). Sometimes present and past tenses are called non-past and non-present tenses. “It is fashionable now to recognize by two tenses

in modern English: a present and a past, or a non-present in quaint new-grammar terminology” (Long, 1966, p.103). As Kilby (1984) mentioned about tense forms “They behave in rather different ways when they are describing events which happened or are expected to happen at some specific time” (p. 16). He believed that aspect forms, perfective and imperfective, could be included as tense systems. Because in the perfective aspect, the normal use will presumably refer to the past event which have occurred, and similarly, in the imperfective aspect, the normal use will be to refer to events, which is in progress. Regarding the correlation and differentiation of tense and aspect, he maintained that,

“The grammatical category of aspect is to be distinguished from tense, in that tense is most obviously an expression of time relative to the time of utterance, whereas aspect expresses the various phases associated with an action or state (or whatever else is expressed by the verb). It is clear that the distinction between progressive forms and simple forms in English (which we shall consider in the next section) is a distinction of aspect, while the distinction of present perfect and simple past is rather more difficult to pin down in terms of such a distinction” (Kilby, 1984, p.

26).

Celce-Murcia et al. (1999) discussed an instructional language learning strategy by English teachers that it is not enough to tell students which there is no future tense in English. Besides, he asserted, “Over the years, the important distinction between tense and aspect has become blurred. Instead, English has been said to have 12 tenses” (p. 111).

The twelve tenses in English are actually combinations of tense, perfective, and imperfective aspects. Therefore, some tenses have the combined names of perfect and progressive. According to Palmer (1974), tense in English has three distinct functions,

“First to mark purely temporal relations of past and present time, secondly in the sequence of tenses that is mainly relevant for reported speech and thirdly to mark “unreality”, particularly in conditional clauses and wishes” (p.43). AbdulFattah (2011) also clarified

“The English tense marks three major functions, viz., temporal relationships,

back-shifting, and tentativeness. The third function is closely related to modal verbs and modality” (p. 39).

Yule (1998) argued there are two tenses of past and present and two aspects of perfect and progressive which are marked in different verb forms of English. According to him, with respect to “situation of utterance, past tense means “remote” and present tense means

“non-remote”. In Yule’s point of view, in the image of stream of time from the past to the future is not the basis of grammatical category of tense. Instead, he proposed the “time of utterance’. “Perhaps a better image would have the time of utterance (speaker’s now) at the center and other referenced situations being viewed as extending in different dimensions of time or possibility away from the center” (Yule, 1998, p. 61).

Sweet (1900) said, “By tense-aspect we understand distinctions of time independent of any reference to past, present or future” (as cited in Korrel, 1991, p. 19). Roberts (1954) asserted that it was oversimplification that Modern English has six tenses in accordance with what is universally recorded in grammar books. “Looked at one way, the language has more; looked at another, it has fewer. But the simplification is convenient and useful, provided that we mind how we use it” (p. 135). In accordance with Willis (1950), aspect is so closely connected with tense that two can be considered together. “Tense is the denotation in a verb form of time of occurrence; and since, simply put, time seems to divide naturally into past, present, and future, three simple tenses might seem sufficient for a language” (p. 161). Likewise, Greenbaum (1996) asserted that aspect is always combined with tense. In addition, Leech & Svartvik, (2003) affirmed, “The present and past tenses can form combinations with the progressive and perfective aspects” (p. 306).

“It is almost universally recorded in grammar books that Modern English has six tenses – past, present, future, past perfect, present perfect, and future perfect. This is an oversimplification. Regarding perfect and imperfect tenses, “There may be other alternative solutions. Leech, 2004, for instance, refers to the ‘present tense’ in English as being ‘psychologically present’ (Kilby, 1984, p.25). Some linguists such as Zandvoort (1969) accounted on progressive forms as verb tenses.