The English language has, without any a doubt, become the most popular publishing language of academic world, according to estimates(Swales 1987:42), approximately half of the published article in the world are written in English, and in some field an even greater number, in Sudan, where it is an important second language taught in schools, it is needed in social interaction in dealing with the foreign countries and gathering information from books and journals particularly at advanced level of education.
Newspapers are a very useful and cheap source of material for language teacher, they are useful for a variety of reasons, primarily newspapers contain examples of authentic written language on a variety of topic, and the language contained in newspapers is also a model of language that students can be asked to analyze, investigate and discus.
Mark Newson (2006) stated that, to explain and understand the difference between lexical and functional categories, we need to know and introduce concepts related with how the part of the sentence related to each other to complete the meaning of that sentence the following example explains that the Professor teaches the students here in this sentence there is an event which can be described as (teaching), and this event is involving two individuals or participants, the professor and the students, and this participants related in a particular way, so the professor is the one doing the teaching and the students are the one getting taught.
Thus the verb describes the character of event and both the professor and the students refer to the elements participated in this event, so the word functions as the verb is so called predicate whereas the one functions as nouns is so called argument, thus what participants (arguments) can be involved in the sentence or event is determined by the meaning of a particular sentence like take for example the following examples:
Stephen is sleeping
John gives Mary some flowers
In these sentence Stephen is only one participant in the event of sleeping, so one argument, but in the second sentence consist three participants which are John, Mary and some flowers, thus three arguments, it clear that from the examples verb like sleep takes only one argument whereas verb like give takes at least three arguments to complete its meaning.
Bas Aerts (2002) posited that English sentences can be described in two ways, functionally and formally, for example the sentence the boy eats banana consist of subject which is the boy and predicator (verb) which is eats and direct object which is a banana, so the subject and direct object are filled by noun phrases whereas the predicator is filled by a verb, so the verb eats cannot form a sentence by itself, but it needs other elements to construct a meaningful sentence, as it clear that from above sentence that eat needs who was done the act of eating something and was being eaten, thus the one who does the of eating and something that was being eaten are so called arguments or participants.
Leonad H. Babby (2009) explained that, one of the most important theories of generative syntax is dealing with the notion that syntax is a projection of the lexicon, mainly to propose explicit theories of the construction between the semantics and morphosytactic structure, he added that â€œit is correct if by lexicon we understand predicate argument structureâ€Â so the sentenceâ€™s main syntactic structure (vP) is immediately projection of verb (v) argument structure, or the argument structure of any sentence based on grammatical (syntactic) relation is determined by the verb (v).
David Adger (2002) stated that the word like teach does not express a complete thought on its own, minimally the word teach expresses a relationship between objects, which one teaches other, in comparison with the word like sleep which needs only one object, the object that sleeps, teach and sleep in contrast with word like gives, which involves three objects, someone gives something to someone, these words express concepts which some of these concepts are necessary to human computational system that related to the meaning of the words, so a predicate can be used in characterization of a situation, but this predicate needs other linguisticsâ€™ elements to complete the thought as explained above with teach, sleep and give.
When a predicate involves one other element to complete the thought then a predicate is one-place predicate like in sleep, and when it needs two or three, then a predicate is two-place or three-place predicate.
By going back to the words sleep, teach and give, we can combine these verbs with other participants to construct the following sentences:
Ali is teaching the girl
Mary gives Nina a pen
In the first sentence the predicate is combined with the theme which is one-place predicate, in the second one the predicate combined with agent and benefactive which is two-place predicate, and for the last one the predicate is combined with source, benefactive and theme which is three-place predicate.
Thus these properties are linguistically so called thematic roles or theta roles which related to the lexicon semantics, so if someone talks about the number of thematic roles that a predicate assigns, he refers to theta roles and each theta roles assigns only one role in the sentence.