In 2017 I made a public vow to start learning Spanish. I kept my promise: I started. But I have since stopped. It is not that the language is difficult. For an English speaker with another romance language, Spanish feels accessible. It was just that I knew it would take years to reach a competent level. Also, the words and grammatical constructions didn’t seem to be sticking the way they once did.

Over the years, I have studied other languages. I started learning French in my thirties. But now that I qualify for free transport in London, am I too old to master another language?

Years of research have established that the best time to start learning a language is in childhood. We have all noticed that while immigrant parents, however fluent they become, retain their accents and make mistakes, their children learn to talk like natives.