This thesis examines the copulas ialah and adalah in Malay on different levels of linguistic analysis, in different periods in time, and against different genetically related languages. Addressing the scarcity of research on copular clauses in Malay in all three areas, namely synchrony, diachrony, and typology, this thesis aims to serve as a point of reference for future study on nonverbal predication in Malay and beyond. The synchronic portion of the thesis begins with a demonstration of the monomorphemic nature of the two copulas, which no longer exhibit the morphosyntax, semantics, and information structure of the morphemes that they appear to comprise, viz. 3rd person ia, existential verb ada, and focus marker lah. Following that, several syntactic and semantic phenomena, including extraction from copular clauses, copular inversion, and overt vs. zero encoding of the copula, are investigated. Lastly, the derivation of clefts in Malay is examined, which I reveal to be a type of copular construction despite the absence of an overt copula. I then show that the derivation of a cleft feeds the further derivation of a pseudocleft via remnant movement. In the history of Malay, ialah and adalah are shown to have emerged relatively recently, that is towards the end of the Classical Malay era, circa the 18th to 19th century. Ialah grammaticalised from the combination of 3rd person pronoun ia and comment marker lah in a topical construction that involved left dislocation. Specifically, the topic was reanalysed as the canonical subject, which subsequently forced the resumptive pronoun to undergo Spec-to-Head reanalysis, resulting in ialah grammaticalising into a copula heading TP. Meanwhile, adalah grammaticalised from semantically vacuous support auxiliary ada, also in combination with comment marker lah. Both copulas originally developed from the need to provide a host for the comment marker as a way of avoiding a violation of the stray affix filter. The typological survey of copular clauses in Austronesian reveals that syntactic alignment and word order play a central role in the emergence of copulas in a language. Of the 40 languages examined, all the 19 languages that have overt copulas are accusatively aligned, except the ergatively aligned Formosan language Puyuma, which entails that ergative-absolutive and split ergative languages within Austronesian are statistically very unlikely to have overt copulas. In addition to that, 20 of the 25 accusatively aligned languages have SVO word order, whilst all of the 9 ergatively aligned languages have VSO word order. The word order of the language is relevant as all but two of the 19 languages with overt copulas have SVO word order. In consideration of these findings, I argue that the correlation among the three factors is such that change from ergative to accusative alignment triggers change in word order from verb-initial order to verb-medial order, and that this is conducive to the emergence of overt copulas. Furthermore, word order plays a crucial role in the emergence of overt copulas as they may develop in topical constructions following reanalysis of the left-dislocated topic as the canonical subject, as argued in the diachronic portion of the thesis. Given this path of development, I argue that pronominal copulas have not been able to develop in the ergatively aligned Philippine-type languages due to the lack of the notion of subject and the absence of the canonical subject position, which prevents reanalysis of left-dislocated topics as canonical subjects and subsequently resumptive pronouns as copulas, as undergone by the Malay copula ialah. In addition to that, verbal copulas cannot develop from posture verbs in the Philippine-type languages because of the clash between the unergative nature of posture verbs and the unaccusative nature of the copula, which presents a problem in the Philippine-type languages due to the encoding of the agent argument on the verb in the actor voice. Besides, the strict intransitive nature of the copular clause is incompatible with other voice alternations such as the benefactive and the locative, as the trigger in these voice alternations is encoded as an applied argument, making the clause transitive. Verbs of becoming also cannot copularise in the Philippine-type languages via semantic bleaching of the inchoative aspect, due to the robust morphological marking of aspect on the verb.