In Arabic spoken in the Yafi region of Yemen, there is a deictic particle, ta, which performs four functions: determining the nominal as a simple demonstrative adjective, it is also equative and attributive linking a specific nominal subject to an indeterminate nominal prediction, presenting a full statement, then the particle designates a proposal as a whole and no longer merely the link between the subject and the preaching, and finally the focal point in the nominal and verbal statements, with values ranging from the contrastive focus of the subject and prediction to the explanation of the situation. It then brings a causal value to the entire predictive relationship. All these functions have in common to call into question the designation and singularisation of a constituent of the statement, which is the semantic invariant of the statement beyond the differences in context and syntax scope.