The present study inspects the semantic and pragmatic meanings of ʔlħin, which is one of the most frequently used discourse markers in informal Arabic. Studies on the discourse marker ‘now’, which is the equivalent of ʔlħin in English, discuss its use as a temporal adverb and a coherence marker. Similarly, the meanings and functions of ʔlħin are examined in this paper. A dataset from Twitter, which is one of the most popular platforms that are rich with millions of conversations between users in all languages, was used to examine temporal and coherence meanings of ʔlħin within different contexts, and whether it works as a constraint on relevance. The analysis showed that ʔlħin conveyed a semantic meaning ‘now’ when used as a temporal adverb to refer to the present time, and was indicative of a pragmatic meaning when used as a discourse marker that has a coherence function. Similar to Schiffrin’s analysis of ‘now’ as a discourse marker, the functions of ʔlħin as a coherence marker include ideational shifting, raising the possibility of disagreement, marking of a reason, engaging in negotiations, and orientation shifts. In relation to relevance, the analysis showed that ʔlħin facilitates the recovery of the most relevant pragmatic interpretation by constraining the addressee’s search for the required interpretation in different contexts.