In Senglea the school grew steadily to about 250 children. Children entered, as now, at the age of 5 and left at 14, when the boys took the examination for entry to the Dockyard. The school's troop of Sea Scouts started about 1910, very soon after the movement began. The old records show that up to 1918 most of the children entering the school were Maltese, but from that time the proportion of English children grew appreciably and as they increased the character of the school changed. In 1925 the level of instruction went beyond the Apprentice Examination and an 'Oxford Junior' class appears in the records for the first time. This was the beginning of a serious effort to run the upper part of the school on secondary school lines as opposed to a preparing ground for Dockyard apprentices. By this time, too, the school had ceased to cater for the children of locally entered Dockyard employees and had assumed its present function of providing education on English lines for children who would normally have gone to English schools. There were now many naval, as well as Dockyard children.

Verdala appears on the scene in 1929. By then there were once again too many children for the Senglea building to hold and an old Royal Marine barracks and ex-prisoner-of-war camp at Cottonera in St Clements Bastion was taken over. This we now know as Verdala School. Here were buildings which would hold 350 children, but the records for 1932 show only 150 boys and 70 girls attending. This number increased steadily to 530 in 1938, when there were three classes of infants, five of juniors, and six secondary. Boys and girls were taught separately in the secondary school in those days. The school also catered for the education of the Dockyard apprentices in the evenings. Top storeys were built on the main Verdala Blocks, in 1938. In those days school lunches cost 6d, and the tuck shop sold lemonade at ld a bottle. The houses for the boys were the same as at present, but the girls had their own houses named Anne, Victoria and Elizabeth.

The school entered its first School Certificate candidate in 1932. He failed, but in 1938 ten certificates were won. This story of growth and development was sadly interrupted by the outbreak of war in 1939, and eventually all English wives and children were evacuated from Malta. The school struggled on in yet another home at St George's Barracks, but eventually shut down completely in September 1942.

During the war the Verdala buildings were badly damaged and the main hall was destroyed. Part of the School was used as a prison, and another part became HMS Euroclydon, and was used to house the crews of submarines.