When to use suffix 'kan'

In the Malay language, there are certain words which must end in 'kan'. These include mengumpulkan / menghimpunkan [to collect), mengendalikan (to manage), memadamkan (to wipe out or to extinguish), menangguhkan (to postpone), merekodkan (to record), menghapuskan (to destroy), membatalkan (to cancel), mempedulikan / mengacuhkan / membenakan / menghiraukan / mengendahkan (to heed), merumuskan (to summarise), melaksanakan (to execute) and menerangkan. Learners of the language have no choice but to to memorise them.

There are other words which need suffix 'kan' only when they act as transitive verbs. These are the examples:
1 a) Dia mengadu kepada polis tentang kejadian itu. [no 'kan' needed]
[He complained to the police about the incident.]
b) Dia mengadukan kejadian itu kepada polis. ['kan' is needed]
[He reported the incident to the police.]

2 a) Kes kemalangan jalan raya semakin meningkat. [no 'kan' needed]
[Road accident cases are on the increase.]
b) Kecuaian pengguna jalan meningkatkan kes kemalangan jalan raya. ['kan' is needed]
[Negligence of road users has increased cases of road accidents.]

3 a) Jangan membazir semasa menggunakan air. [no 'kan' needed]
[Don't waste when using water.]
b) Dia suka membazirkan air semasa mandi. ['kan' is needed]
[He likes to waste water when bathing.]

4 a) Dia mencuba mengelak apabila nampak musuhnya. [no 'kan' needed]
[He tried to avoid when he spotted his enemy.]
b) Dia mengelakkan kereta yang dipandu ke arahnya itu. ['kan' is needed]
[He avoided the car that drove in his direction.]

5 a) Azmi suka menyanyi semasa mandi. [no 'kan' needed]
[Azmi likes to sing when he bathes.]
b) Mazlan menyanyikan lagu itu berulang-ulang. ['kan' is needed]
[Mazlan sang the song repeatedly.]

6 a) Lelaki itu suka menderma apabila dia mempunyai wang yang berlebihan. [no 'kan' needed]
[The man likes to donate whenever he has surplus money.]
b) Lina mendermakan dua ratus ringgit kepada mangsa banjir itu. ['kan' is needed]
[Lina donated two hundred ringgit to the flood victim.]

7 a) Suaranya meninggi apabila dia meradang. [no 'kan' needed]
[His voice was high / loud when he got angry.]
b) Dia meninggikan suaranya semasa memarahi anaknya. ['kan' is needed]
[He raised his voice when he scolded his son.]

8 a) Tangannya menghulur semasa dia bersenam. [no 'kan' needed]
[His hands straighten when he is exercising.]
b) Johari menghulurkan buah rambutan kepada jirannya. ['kan' is needed]
[Johari gave rambutans to his neighbour.]

9 a) Lilin yang bernyala itu semakin memendek. [no 'kan' needed]
[The burning candles became shorter and shorter.]
b) Dia meminta tukang rambut itu memendekkan rambutan. ['kan' is needed]
[He asked the barber to shorten his hair.]

10 a) Kakak suka mengurus halnya sendiri. [no 'kan' needed]
[My sister likes to manage her own things.]
b) Ibu menguruskan adik hal pendaftaran di tadika itu. ['kan' is needed]
[My mother did the registration at the kindergarten for my younger brother.]
c) Badan pesakit itu mengurus selepas seminggu. [no 'kan' needed]
[The patient's body became thin after a week.]
d) Lelaki gemuk itu menguruskan badannya dengan selalu bersenam. ['kan' is needed]
[The man slimmed his body down by exercising regularly.]