The history and development of the Manado language cannot be separated from the Malay language that first developed in the neighboring province of North Maluku. Centuries ago, the Malay language known as "Bazaar" Malay was brought by traders from Riau and Johor in western Indonesia to North Maluku. The traders were from western Indonesia, south Sulawesi, and also from middle eastern and European countries. All of the traders who brought and used this Malay were not native speakers. They used this trade language as a second or third language, often adding words and grammar to it from their own mother tongue. And likewise the native people of North Maluku also used this trade language as non-native speakers, adding their own words and grammar to this language. This phenomena is called creolization, the accepting of words and grammar from multiple languages into another language. We can see words and language patterns from the local languages like the Ternate language, and also from the outside languages like Portuguese, Spanish and Dutch. So the first wave of creolization on the Manado language actually took place in North Maluku, with other languages influencing this Malay trade language.
In the 1500s, traders from North Maluku began to come to North Sulawesi. They used this Malay trade language as a language of communication between people of different ethnic/language groups. And at that time the people of North Sulawesi also began to use this language to communicate with the traders who had just arrived. And just like in North Maluku, the people of North Sulawesi also began using some words and grammar from their own local languages, influencing the Malay trade language that would later be called the Manado language or bahasa Manado. This was the second wave of influence in this creolization process.
This process of creolization is a common phenomena when a language from the outside is used as a trade language to help in the communication between multiple ethnic/language groups. One step within the creolization process is called piginization. In this step the verb affixation is simplified. Common prefixes such as meng- and di- and the suffix -kan are no longer used, but are replaced by words like kase and beking to show causative, examples: memberi makan --> kase makang, and memanaskan ---> beking panas.
Another Malay based language is the Indonesian national language, bahasa Indonesia. The national language was formalized in 1940s, a late-comer to the North Sulawesi language scene. The national language is based on a Malay language that was used within the royal palace in Riau and Johor a few centuries ago. So the national language and the Manado language are both Malay languages, but they are based on different types of Malay languages. Plus, the history of the two languages are vastly different. Both of these languages are very important within the lives of the people of North Sulawesi, and both are worthy of study and development.