Second language learning can be listed in two ways: simultaneous and sequential learning (Halgunseth, 2010). Simultaneous learning involves younger children who are exposed to more than one language since birth. However, this type of learning is categorised under bilingualism. Second language learning is more of a sequential learning in either a naturalistic or formal setting. This involves children who are already familiar with one language then introduced to another at the later part of their childhood. A naturalistic setting may include language learning in the neighborhood when the child might meet and mix with children who speak other languages; or more commonly, in a more formal setting like school. Take for example, in the Singapore context, a child who speaks Mandarin Chinese at home but is required to learn English in school. This change might trigger some stages of learning in child SLA. At the initial stage, when a child is newly exposed to a new language, it is normal for him to persist using the first language even though the others do not understand. When the child realizes that he is not understood, he will enter a stage where he chooses to communicate nonverbally instead of verbally. At the next stage, the child will start speaking in small utterances using the new language. At the final stage, when the child has already acquired enough of the second language, he will be able to construct sentences to express themselves. Although the sentences might be very basic or contains grammatical mistakes in the beginning, it will gradually improve overtime.
HS moved with his Korean family to Singapore at the age of 4. He entered a local kindergarten at the Nursery level. When he first came to school, he communicated with the teachers in Korean. However, after he realizes that he is not understood and the teachers kept asking him to speak in English, he decided to not speak at all and start pointing to things to communicate. After a period of time, he was able to start saying single words like: toilet, please, teacher, no, yes etc. Slowly, he started to speak in longer sentences like: Teacher, I want toilet. This is an example of a child who went through all four stages of SLA through sequential learning.