Shopkeeper Francisca Reguero is used to sorting out tricky problems for her customers.
Since the euro was introduced just over a year ago, she has spent much of her time explaining prices in the new currency to many of the older people who visit her estanco or tobacconist shop in the small village of Capileira in southern Spain.
But today she faces a rather different challenge. Her customers include three British students, including myself, who arrived in Capileira two days earlier and are spending a week learning Spanish in the glorious setting of the Sierra Nevada mountains.
We are accompanied by our teacher Ramon Alvarez who, like Senora Reguero, does not speak English. When I met Ramon at Malaga Airport and he began asking me questions in Spanish, I thought that it was some sort of early test. It was only later that I discovered we would be communicating in Spanish throughout the week.
Things go pretty well in the estanco as we ask for stamps to put on our postcards. Senora Reguero is understanding about some of our less-than-perfect pronunciations. "It's better to learn Spanish here in Spain," she says.
Elsewhere in the village, other students are practising Spanish by asking directions to the museum, or supermarket. Many residents are familiar with being bit-part players in students' practical assignments and do not seem to mind any slight inconvenience.
Capileira, with a population of 900, sits neatly towards the top of the beautiful Alpujarra region and is about two hours by car from Granada.
British students have been going to the village since May 2001 after Patsy Pilkington, who lives in Dorchester, Dorset, set up a company called The Spanish Experience.
For around pound;500, they receive five mornings of tuition, along with hotel accommodation, evening meals and the chance to join organised walks.
Air fares are extra.
This week I am one of a total of seven students who are split into three groups according to our level of Spanish. Ramon Alvarez takes the most advanced group where discussions cover everything from farming in Spain to sex discrimination at work.
The challenge of being forced to speak in Spanish, and check words we do not understand by finding alternative words in Spanish, is quite unlike anything I have experienced during three years of studying the language in the UK - most of it in evening classes at a college.
Fortunately Senor Alvarez, who has been a teacher for 12 years, speaks more slowly and clearly than probably any Spaniard you will ever meet. He trained himself to speak at half his normal speed to help students and regularly accentuates difficult words.
Senor Alvarez prefers teaching adults who already understand a little Spanish because, he says, they spend more time discussing politics or culture. Grammar is inter-woven into the lessons, but the emphasis is on conversation through the so-called "natural approach".
"Grammar is important at the same time as you are talking," he explains to me in the first interview for The TES that I have conducted entirely in Spanish. "I tell my students that meeting me is like meeting the man in the street here who doesn't speak any English."
Walking around the village, hearing Spanish being spoken in the bars and shops, helps vocabulary come flooding back. Suddenly verb endings do not seem so much of a nightmare either.
Josephine Boath, a chartered secretary from London, learnt Spanish more than 30 years ago and joined the programme to refresh her memory before buying a holiday home in Spain. "It is great to be able to hold proper conversations rather than just to speak 'pigeon' Spanish," she says.
Although the other two teachers speak English as well, they also spend most of their time speaking in the language they are trying to teach. Pilar Ruiz, who trained as a teacher in Spain before spending a year working at a school in Northampton, admits she had to refine her accent. "You change the micro-chip in your head. You have to speak slowly enough for the learners to understand without it sounding silly."
Every student has a story about the moment they knew they had moved to a new level. In the case of Pat Brafield, a former French teacher from Kent who did not speak any Spanish before she went to Capileira, it came in a shop in Granada's Alhambra Palace.
"A man asked me a question and I knew the answer because it was something that we had learnt in class," she says.
Jo Holmes, who trained as a teacher in England, is working with two students who, just days earlier, hardly understood a word of Spanish. Where there is confusion she uses words such as los canales that sound the same in both languages. To demonstrate thirst, she points to a bottle of water on the table while, in the case of beauty, she points to las montanas across the valley.
Ms Holmes is in no doubt that students learn more quickly in a country where they hear the language being spoken all the time.
She says. "Here it seems more natural to be speaking Spanish. I never have to tell the students to go off and learn."
Neil Merrick visited Capileira as a guest of The Spanish Experience. Tel: 01305 262702www.thespanishexperience.com