At age 11, most struggle with stretched and sprawling, but most can spell tallest. Eleven-year-olds are good at reading statistics but even the brightest have trouble with percentages and fractions.
In science, they are confident about electricity but give poor answers to questions about why the sun appears to move across the sky.
At age 14, pupils tend to confuse of/off and there/they're/ their. Many have difficulty forming the past tense with "ed", and even brighter pupils sometimes use commas when full stops are needed.
In maths at this age, basic number work is solid but algebra is weak. Multiplication is also a problem. In science, they are better at biology than chemistry. In physics, fewer than a third know that the sun appears lower in the sky in December than in March.
The survey of the tests taken by 500,000 pupils aged 7, 11 and 14 last summer was carried out for the School Curriculum and Assessment Authority.
Overall, the results showed a slight improvement on the previous year in English, maths and science. At age seven, more children were reaching the level expected in maths and more did better in the reading comprehension test. About eight out of 10 reach the expected standard in all subjects.
Results for 11-year-olds were also better than in the previous year in English and maths though in science they were worse because the test was made harder.
At age 14, the proportion reaching the level expected in English rose by 2 per cent to 57 per cent but more reached one of the higher levels than in the previous year. In maths, the percentage reaching the standard expected fell by 1 per cent.
In science, the proportion remained the same as the previous year but fewer pupils reached the highest levels.
Dr Nick Tate, the authority's chief executive, said the reports were a powerful tool for improving teaching and raising standards. He acknowledged concern that nearly half of primary pupils were not doing as well as they should but said: "The improvement in the standard has a long way to go but at least we are moving in the right direction."
He dismissed suggestions that results were improving simply because teachers were teaching to the test. "If we get the tests right then teaching to the test is exactly what we want."
Later he added: "When tests were first introduced, revision was a dirty word. It is no longer so. People have rediscovered the idea. Some of us might be surprised that it was ever forgotten."
Dr Tate has been appointed as head of the new Qualifications and National Curriculum Authority, the Government announced yesterday. The body will advise ministers on both academic and job-related qualifications as part of the drive to bring them closer together.
% spelling words correctly
Many 11-year-olds had difficulties with these questions.
The family throws away 130kg of paper and card. Seventy per cent of this is newspapers. What is the weight of newspapers?
Write in the missing digit
?7 x 9 = 333
Ten books on a shelf take up 28 centimetres. What is the average thickness of the books?