They function with the linguistic system to establish the relationships between grammatical units in a discourse. This language concept defined differently by many scholars and it has a high frequency in linguistics. Scholars used this word when they want to refer to an extant more than one sentence. As Sadeghi and Kargar (2014) said "discourse means consistency in a language; so, just a chain of words and sentences do not create a discourse" (p, 328). A text is considered constitute if there is a relationship between and within the sentences, if not they would be just some unrelated sentences. These relations are called cohesive relations which interlinked the different parts of a text in different ways (Yule & Brown, 1989 as cited in Khatib 2011). Discourse markers (henceforth DMs) are relatively syntax-independent and have empty meaning (Schiffrin, 1986). They also called linking …show more content…
Ellis (1995) maintains that noticing is important for the acquisition of both form and meaning of target form which facilitates the process of learning. (Petchko, 2011, p. 232). As Schmidt (1993) and Sharwood-smith (1993) claimed, the idea which is supported by input enhancement or conscious raising task is that some aspects of L2 input are shown more saliently so the students notice the target features and in this way more chance is provide for learners to convert input into intake (as as cited in Rahimi, & Shabani 2015). Different techniques have been designed to draw student 's attentions to formal features of second language input. These techniques are called "conscious raising" which promotes noticing that improves learning. For the first time in (1993) Sharwood-smith introduce a concept of "input enhancement" which is refers to the role of grammar in second language, after that this concept gets more general definition and it can be used for lexical items as well