Gill Bal understands the culture shock of arriving at a secondary school in Britain speaking little English. The 48-year-old headteacher grew up in India as a Punjabi speaker, then moved to London when she was 13.
"It was a completely alien world," she said. "You are in a foreign country, with a different culture, and different way of doing things and you have to learn very, very quickly."
There are few schools where Ms Bal's experience would be more useful than Wembley High, where 1,009 of the 1,343 pupils speak English as an additional language.
Yet her understanding of her pupils is only one of the reasons why the school has been described as the most improved in London.
When inspectors visited in 1999 their report began with three words: "Weaknesses outweigh strengths." They went on to remark on the school's poor results and misbehaviour in its corridors.
This week Ofsted published a dramatically different report, describing Wembley High as "a really outstanding place to be". It rated 24 out of 27 aspects of the school's work as outstanding and quoted a former parent who said the school's changes had been "an absolute joy to watch".
So what has changed? Not the intake, it seems. More than a third of the pupils are still eligible for free school meals, and their nationalities are as varied as before, with 56 different languages spoken.
The inspectors suggested that improvement was down to an "unrelenting determination" among all the staff to "maximise student's life chances".
Ms Bal recalls that when she arrived at Drayton Manor High School in Ealing, west London, as a teenager in the 1970s she was placed in a CSE class for English.
But a deputy head spotted her potential, and moved her into an O-level class in Year 11. "I think he understood that your ability to speak English is not a reflection of your academic ability," she said.
Ms Bal believes if it had not been for his decision, she would not have gone on to do A-levels, a chemistry degree at Royal Holloway College, and then train as a science teacher.
As a result, she refuses to describe her pupils' lack of English as a first language as a barrier to learning and insists her staff set all students stretching targets.
Wembley High is heavily target-focused, conducting regular tests every half-term and providing parents with tracking reports every term, updating them on their children's results in every subject.
Pupils are encouraged to sit several GCSEs a year early and then resit them if there is a chance to lift their grade to an A or a B. This year 88 per cent gained five top grades.
The focus on scores might seem excessive to some teachers, but staff at the school say there is great pride among pupils and parents in their achievements. Back in 1999, inspectors said that Wembley High had not been a first choice for parents for years. Now there are four applicants for every place.
The inspectors noted how the students had become proactive, recently starting a knife crime awareness campaign, involving posters and assemblies, in reaction to the high number of young people stabbed in London. It also stressed that improvements were not just the result of the Wembley's headteacher, but because "everyone pulls in the same direction".
Edward Bowes, a 17-year-old A-level pupil, said he had noticed the change in teachers' attitudes.
"I was pretty scared when I first came here," he said. "The biggest thing has been that the staff seem more dedicated now, more prepared to do extra work to help pupils out - and crack down when rules are broken."
The most with Teach First
Wembley High has more teachers on the Teach First programme than any school in Britain - participants account for a quarter of its teaching staff.
The school was one of the first to volunteer for the scheme, in which graduates from high-performing universities spend at least two years in the classroom. It has succeeded in retaining 23 of them, and some have been promoted to roles as senior assistant head.
Gemma Bayes, 24, head of modern foreign languages, said her first days had been nerve-wracking, but that other teachers had been highly supportive.
"It was the hardest thing I have ever done in my life, and we were prepared for it being hard" she said. "But it was also the best thing I've done."
Steve Bullock, 26, head of physics, said that, ironically, many London schools now regarded Teach First graduates as a source of consistency, because they were guaranteed to stay in the same school for two years.
He had been concerned he might be treated differently by other teachers, but said that "the atmosphere at Wembley is that everyone is all in it together".
Brett Wigdortz, chief executive of Teach First, is also one of Wembley High's governors. He said the ethos of the scheme was in line with the school's aims. "I think in the past people had too low expectations, and a core part of Teach First is to have high expectations for all children," he said.