This is the 317th most frequent Malay word.
kalau
"If" or "when" (depending on context).
The word 'kalau' is used here as a conditional 'if' to indicate a condition for the action.
Kalau hujan turun, kita tidak boleh bermain di luar.
If it rains, we cannot play outside.
The word 'kalau' is used to express a conditional situation relating to the availability of free time.
Dia akan pergi ke taman kalau dia ada masa lapang.
She will go to the park if she has free time.
The word 'kalau' appears in a hypothetical condition to express a wish or an unreal situation.