Foreign phrase books must be the least referred to of all reference books. Whenever I conscientiously buy one, it slumbers in my suitcase unconsulted. As a marketing ploy, Destination Spanish (and its cousins, Destinations French and Italian) could not be cannier. These new language courses pitch themselves as replacements to phrase books. In 150 minutes, with two CDs and a follow-up booklet, they teach tourist vocab and rudimentary conversation. They even boast that you can do the courses on the plane and be up to speed as you disembark. The idea is that they turn your head into a phrase book. But languages take years of slog to master. 150 minutes? No chance, I thought.

I have a lousy memory and am a beginner at Spanish. I put on the first CD with caution at home. Paul Noble – mastermind behind the series – has a voice that is slow, clear, reassuring. He seems to have low expectations of his students (telling us not to rush or worry about our errors). I rather liked this, though some students might take umbrage. He reminds me of a hypnotist in that he works with unconscious recall. What he tells you – and this is the interesting bit – is not to remember. You do not make any effort beyond listening and repeating. Repetition is key. Sentences are skillfully built up. There is no overt grammar (Michael Gove would not approve).

But at the end of the CDs, I found that language had been placed in my head – it reminded me of the methodical way my husband stacks the dishwasher. The Spanish had stuck. I enjoyed ordering imaginary paella in the privacy of my study, reserving rooms with baths, asking imaginary people whether they had visited Barcelona and getting the soft pronunciation of mesa (table) right following the lead of patient Castilian Carmen. Noble also gives you a pick 'n' mix of adjectives effortlessly converted: exótico, politico, romántico. Spanish is a hospitable language for English speakers.

But it is one thing to trot out these phrases at home, another to air them abroad. As I landed early in the morning at Madrid airport, I was seized by stage fright. I needed directions to the luggage storage, as I had time to kill and hoped to visit the Prado. This meant departing from the script, because la consigna was not on the CD (I spotted it on a sign).

Quisiera (I would like) is the word with which Noble launches us upon Spain (alarming that tourism should boil down to such an acquisitive word). "Quisiera la Consigna por favor?" The official responded but I did not understand a word. I realised then that my Spanish was equivalent to a handful of small change – not proper currency. But also that it was far better than nothing: I valued the security of knowing I had phrases that, in the proper context, would be understood, with pronunciation that would not disgrace me. What's more, the Spaniards I came across were encouraging, unsnooty and often visibly pleased when I made it clear I preferred to stagger on in Spanish rather than lording it over them in English. It made me ashamed to think how often I have behaved as if it were my right, as an English speaker, to be understood everywhere.

I clung on to quisiera like an old friend – until I got verb fatigue. I had low moments when, in my determination not to cheat with English, I collapsed into panicky French. On taxi rides to and from the Prado (half-hour tutorials), I asked drivers: "Ha visitado Londres?", as if conducting a survey, and invited incomprehensible torrents of Spanish in response. But making the human connection felt great – even if my obsession with asking people which cities they had visited wore thin. At the Prado's cafe, I unveiled one of my more complicated sentences: "Quisiera pagar con tarjeta de credito por favor" (I would like to pay with a credit card, please). In practice, this sounded pompously overlong (couldn't I have waved my card at the cashier?), but I was elated at being understood.

Post Madrid, I joined a horseback ride for a couple of days in Segovia, just north of the capital. It was Maria Elena – its vivacious organiser – who explained that Spanish is direct: you can go a long way on a noun and a "por favor". Her colleague, Enrique, was a living reminder that in Spain "horseman" and "gent" go together. A caballero who spoke no English, he was to be my interlocutor. He looks like a superbly turned out businessman, keeps an immaculate stable, has an impish smile and rides like a man possessed. He made me long for fluency. Out of such frustration, one learns in earnest.

Riding through Castilian countryside at an exhilarating pace, Enrique taught me some fine Spanish curses and: "hombre!" (Good heavens, man). He also tried to involve me in an excitable conversation about mules that stretched Destination Spanish beyond its limits. And yet, as I kept discovering, if you keep adding vocab to your foundations, Carlos is – or will be in time – your uncle. We rode past mediaeval hilltop villages and I learned to exclaim: "Muy precioso!" We saw Romanesque churches (iglesias), vultures (buitres) and violets (violetas – easy). I even gave: "Quisiera saber si es romántico?" (I would like to know if it is romantic) a spin – a question that hardly needed asking in Segovia in the spring.

Back at Luton airport, I almost ordered a coffee in Spanish by mistake. Destination Spanish was hanging on in there. The course does not pretend to give you complete command of the language, but it is a way in, an ice-breaker – and it is superior to any phrase book. I found it frustrating in a good way – it has made me thirsty for more. And no es problemático: Noble has a 13-hour – interminable by his standards – follow-up course, at the end of which I plan to speak Spanish like there is no mañana.

• Destination Spanish with Paul Noble: Spanish in 150 minutes (Collins, £12.99). Also available in French and Italian. The horse riding was provided by Ride World Wide (01837 82544, rideworldwide.com) which offers a week's riding in Segovia from £2,000pp per week, including transfers, four-star accommodation, riding and guides