WHEN Pearlyn Ler returned to Singapore to start Primary 5 after four years in the United States, she could hardly understand a word on the Chinese news bulletins.

Her aircraft technician father had taken his wife, a homemaker, Pearlyn and her younger brother to the US when he was posted there in the 1990s.

The Singapore Chinese Girls' School (SCGS) student got an A2 for Higher Chinese - the only blemish in her O level results slip, which was given out on Thursday.

She scored a string of 9A1s and 1A2, making her one of two top O-level students this year.

On her American schooling experience, which Perlyn described as fun, she said it helped her build a strong foundation in English.

'Everybody spoke grammatically correct English most of the time,' said Pearlyn.

But her command of the mother tongue suffered.

When she returned, she worked hard to brush up her Chinese by speaking Mandarin to her cousins and taking tuition. From scoring C5 or B4 for Higher Chinese, she went on to snare an A2.

Language also proved the 'Achilles Heel of the other top student, Kim Chan Xinhui, 17, from Methodist Girls' School.

She had A1s for all except Japanese, for which she scored A2.

The former Girls' Guide platoon leader could have gone to an Integrated Programme (IP) school where she did not have to take the O levels but chose not to.

'I can fall back on it,' said Kim, the youngest of three children of an engineer and insurance manager.

The two top students stood out for being Singaporean, as this year's pick of the O-level crop featured 11 foreigners out of 19.

In the past few years, foreign students, especially scholarship holders, have swept the board after top Singaporean students opt for the IP route bypassing the O levels.

The top students from Catholic High and Crescent Girls - six in total - are all foreign students on scholarship.

Hu Yiqing, 18, the only child of a government official and university professor came from Jiangsu on a scholarship, and started at Sec 3 in Crescent Girls.

And like most of her China peers studying here, she struggled in English initially.

'There was one time I went to MacDonalds and I wanted French Fries but I was so blur I asked for Fried Rice,' said Yiqing, now at Hwa Chong Junior College. Catholic High's Tan Tzer Han, 17, from Penang, had to work on his English too, when he got a scholarship to study here at Sec 3.

He failed his first English test, but started compiling wordlists which he would memorise by hard, and reading an English book every few days.

The top scorer among the Secondary 5 students is Beetsma Dina Husna Zamily, of Swiss Cottage Secondary School, who obtained 6A1s and an A2.

Her results were the best ever scored by a Normal (Academic) stream student sitting for the O level exams.

The former Woodlands Primary student could have gone to the Express course with her PSLE aggregate score of 186, but chose the Normal stream so that she could be with her elder sister Sufyani in Swiss Cottage.

She topped her cohort in Secondary 2 in 2004 but her grades were not good enough to make the switch to Express stream.

That year, her sister emerged the school's top N level student taking the O levels, with six distinctions - 4A1s and 2A2s.

Like her sister, Beetsma wants to go to National Junior College, and make it to university.

Altogether, 48 secondary schools have students scoring 7A1s or more.

Of the 38,450 students who sat for 2007 O-level exam, 99.9 per cent or 38,402, have been awarded certificates.

Among them, 3,516 or 30.2 per cent of the 2007 Secondary 4 Normal (Academic) students sat for one or two subjects in the O-level examination. Of these, 91.7 per cent passed.

The O level exams is conducted jointly by the University of Cambridge Local Examinations Syndicate, the Singapore Examinations and Assessment Board and the Ministry of Education.