When German GCSE candidates start humming She’ll be Coming ‘Round the Mountain during their oral, the examiners should not be too surprised - the pupils are just trying to remember how the past tense goes.

Heidi Behrens, German teacher and website creator, thinks setting grammar to a familiar tune is an ideal way to learn it and to remember those pesky verbs. And verbs, as she remarks, are vital to help pupils manipulate the language.

The words she has set to the tune of She’ll be Coming ‘Round the Mountain describe activities teenagers might have got up to last weekend, complete with a refrain describing them as great (toll) or boring (doof). “It saved the bacon of my Year 11s in their oral this year,” says Heidi. “They just had to adapt the odd word and they could keep going.”

The song is available online on her website called klar (meaning clear), sung by Heidi herself. But today, her Year 8 class at Waldegrave School for Girls in Twickenham, west London, is singing a different tune. The pupils are getting to grips with the present tense of irregular verbs, and what better way could there be to conjugate sehen (to see) than to chant it to the tune of You are My Sunshine?

Heidi concentrates on verbs because she found, when she started teaching Year 10 and 11 pupils, that this was their weak point. But her class is soaking up a lot of other grammar and vocabulary, too. They revise 12 hobbies, such as cycling and skating, with the aid of extracts from her website on the interactive whiteboard, but they also learn by absorbing her instructions and questions, given in German.

German-born Heidi came to England in her twenties as a bilingual secretary.

She then studied and trained as a teacher. Was she shocked by how little grammar English pupils knew? “You get used to it, don’t you?” she replies, diplomatically. “But you can’t learn German without grammar.”

When she started teaching German in schools in Surrey and the London borough of Richmond, she found few online resources to help and felt textbooks tended to cover grammar rather as an afterthought. So she decided to go part-time and create her own website, setting out grammar and vocabulary in a coherent way and making the whole process as interactive as possible.

The website includes PowerPoint slide shows on vocabulary and grammar; exercises and practice games, including hangman; and reading and listening tasks. Heidi speaks (or sings) the words.

Visiting her class is like visiting the website - not surprisingly, since everything on it has been tested in class. If it doesn’t work, it doesn’t go online. Nearly everything seems to help her Year 8 class at Waldegrave.

The lesson is highly interactive in every sense - ranging from whole-class question and answer sessions, through individual writing, working in pairs and collective singing, to a final anagram session, where four pupils come to the front to write the correct verb on the whiteboard, egged on and applauded by their peers when they get it right.

One person who resists Heidi’s teacherly charms is her English husband, who knows not a word of German. There’s still hope: their 16-year-old daughter gave him a German GCSE revision manual last Christmas www.klar.co.uk for teaching German in school and independent study at home.

Users logging on between 9am and 4pm, Monday to Friday, need to pay a subscription (pound;50 for 12 months)