 Households were forced to turn to secondary crops such as sweet potatoes, yam and tapioca for their own subsistence.Beginning in 1942, a standardised Japanese curricula was enforced in all schools throughout Penang, with Japanese as the official language.In fact, social lifestyles were also greatly impacted, as it became compulsory to bow to Japanese soldiers on guard duty and to sing the Japanese national anthem, whilst whole streets and shops were renamed in Japanese.