دخول (ليس)‎ على الفعل الماضي بين التنظير النحوي و الاستعمال اللغوي

الملخص EN

The Arabic word ( ليس ) lies in a different classification of the grammatical devices.

A team of specialists considers it as a verb, another team claims that it is a letter and a third team deals with it according to the structure where it appears.

Accordingly, it appears as a verb or a letter while some modern researchers state that it combines features of both the verb and the letter and having the features of the letter overwhelmingly.

But, the modern classification considers it as not more than an element of negation that changes the affirmative sentence into a negative one.

The difference of its classification sheds its light on the significance of tense.

Most grammarians find that it is concerned with the negation of the adverb or with the adverb and futurity by some others.

While, other grammarians state that it negates the futurity.

The fourth team, on the other hand, mentions that it is used with absolute negation, and the tense of negation is determined by its evidence.

They tackled also the structures where it appears stating that it is not used with the past tense and if this happens it will be an exception.

But, the investigation in this regard proves the reverse since evidence shows that it appears with the past tense to prove that this structure is common in language use, otherwise how does it come that it is found in most speeches of eloquent Arabs?