The most common arguments in favour of a relationship between Indo-European and Uralic are based on seemingly common elements of morphology, such as the pronominal roots ("*m-" for first person; "*t-" for second person; "*i-" for third person), case markings (accusative "*-m"; ablative/partitive "*-ta"), interrogative/relative pronouns ("*kʷ-" "who?, which?"; "*y-" "who, which" to signal relative clauses) and a common SOV word order. Other, less obvious correspondences are suggested, such as the Indo-European plural marker "*-es" (or "*-s" in the accusative plural "*") and its Uralic counterpart "*-t". This same word-final assibilation of "*-t" to "*-s" may also be present in Indo-European second-person singular "*-s" in comparison with Uralic second-person singular "*-t". Compare, within Indo-European itself, "*-s" second-person singular injunctive, "*-si" second-person singular present indicative, "*-tHa" second-person singular perfect, "*-te" second-person plural present indicative, "*tu" "you" (singular) nominative, "*tei" "to you" (singular) enclitic pronoun. These forms suggest that the underlying second-person marker in Indo-European may be "*t" and that the "*u" found in forms such as "*tu" was originally an affixal particle.