As a science of text, text linguistics describes or explains among different types of text the: * Shared features
* Distinct features
Text linguistics is the study of how texts function in human interaction. Beaugrande and Dressler define a text as a “communicative occurrence which meets seven standards of textuality” – Cohesion, Coherence, Intentionality, Acceptability, Informativity, Situationality and Intertextuality, without any of which the text will not be communicative. Non-communicative texts are treated as non-texts.  Cohesion
Surface texts are the exact words that people see or hear. Cohesion concerns the ways in which the components of the surface text are connected within a sequence. Grammatical forms and conventions are adhered to by surface components and therefore cohesion rests upon grammatical dependencies. The grammatical dependencies in surface texts are major signals for sorting out meanings and uses. Cohesion encompasses all of the functions that can be used to signal relations among surface elements. “| SLOWCARS
HELD UP| ”|
Such a text can be divided up into various dependencies. Someone might construe it as a notice about ‘slow cars’ that are ‘held up’, so that conclusions could be drawn about the need to drive fast to avoid being held up. However, it is more likely for one to divide the text into ‘slow’ and ‘cars held up’, so that drivers will drive slowly to avoid accidents or take alternative routes to avoid being caught in the slow traffic. A science of text should explain how ambiguities such as this are possible, as well as how they are precluded or resolved without much difficulty. For efficient communication to take place there must be interaction between cohesion and other standards of textuality because the surface alone is not decisive.  Coherence
Coherence concerns the ways in which concepts and relations, which underlie the surface text, are linked, relevant and used, to achieve efficient communication. * A concept is a cognitive content which can be retrieved or triggered with a high degree of consistency in the mind * Relations are the links between concepts within a text, with each link identified with the concept that it connects to Surface texts may not always express relations explicitly therefore people supply as many relations as are needed to make sense out of any particular text. In the example of the road sign ‘SLOW CARS HELD UP’, ‘cars’ is an object concept and ‘held up’ an action concept, and the ‘cars’ are the link to ‘held up’. Therefore, ‘slow’ is more likely to be interpreted as a motion than as the speed at which cars are travelling. Types of relations include: I.Causality “| Itsy Bitsy spider climbing up the spout. Down came the rain and washed the spider out| ”| The event of ‘raining’ causes the event of ‘washing the spider out’ because it creates the necessary conditions for the latter; without the rain, the spider will not be washed out. II.Enablement “| Humpty Dumpty sat on the wall, Humpty Dumpty had a great fall| ”| The action of sitting on the wall created the sufficient but not necessary conditions for the action of falling down. Sitting on a wall makes it possible but not obligatory for falling down to occur. III.Reason “| Jack shall have but a penny a day because he can’t work any faster| ”| In contrast to the rain which causes Itsy Bitsy spider to be washed out, the slow working does not actually cause or enable the low wage. Instead, the low wage is a reasonable outcome; ‘reason’ is used to term actions that occur as a rational response to a previous event. IV.Purpose “| Old Mother Hubbard went to the cupboard to get her poor dog a bone| ”| In contrast to Humpty Dumpty’s action of sitting on the wall which enables the action of falling down, there is a plan involved here; Humpty Dumpty did not sit on the wall so that it could fall down but Old Mother Hubbard went to the...