Nothing exceptional in that, you might say. Those of us with daughters regard this is a perfectly logical step in the life-cycle of a family. But the man in question belonged to a community which in one important way was very different from my own.

Getting to know him and his way of life opened an Aladdin’s cave of discovery to me. So what was special about him? Was he a millionaire, a media star, an alien? No, he was profoundly deaf. My daughter has perfect hearing but had chosen to work within the deaf community, where she met her future husband. They fell in love and, three years later, became man and wife.

My education in the field of deaf awareness began during the early days of their relationship. Learning to communicate with a person who could not hear my voice was a new experience for me. Lip-reading, British sign language and facial expressions are crucial, of course, but it’s so much more than that.

I became acutely aware of the huge capacity of my future son-in-law and his deaf friends to express themselves in non-verbal ways. Their ideas, opinions and emotions were being given full rein, but in silence. To me, with my background in language teaching, this was stunning. Like most people, I’d always known such non-verbal communication existed, but I’d had no close contact with any of its practitioners. Certainly, I was sublimely unaware of its power and dynamism.

Seeing deaf people at work and at play opened my eyes to a world in which sound had no place, but which was as vibrant and dynamic as the world I knew. I will never forget the enthusiasm and joy radiated by the large number of deaf guests at my daughter’s wedding. Their humour, vitality and sheer individual and collective personality helped to make a memorable event a truly unforgettable one.

The birth of a daughter to my daughter and son-in-law has further illuminated the issue of communication. Seen through the rose-coloured spectacles issued to me on her arrival, my granddaughter is exceptional. Like her mother, she has perfect hearing but, being born into a family where communication through speech and sign language is the norm, she is being brought up to be bilingual. Everything that is said to her is signed simultaneously.

Now, at the age of 11 months, in common with any number of other children of her age who are similarly exposed to signing, she can recognise some basic signs: “mummy”, “daddy”, “washing machine”, “telephone”, “cat” and so on. She replicates them when prompted but also produces them when she feels the need. For example, she recently made the “Y” sign (right forefinger placed at the junction of the left thumb and forefinger) to indicate that she wanted some yoghurt. And she often indicates “home” (hands placed together to indicate a roof) when she enters the house.

What is fascinating to me as her adoring grandfather and as a professional linguist is that her signing ability is developing before any serious verbal competence. Not being an expert in child development, I can offer only a layman’s view, but the fact that signed communication seems possible before speech acquisition surely indicates the potential of a young child’s brain. Giving all young children access to this means of expression would be a positive step.

I have taught children whose parents are of two nationalities and who have become bilingual, and thus had an advantage over those who have learned a second language at school. In a world in which there is an increasing need to communicate with those from other cultures and backgrounds, there could be a lesson for us here.

I may be an experienced and long-serving language teacher, but I am certainly still learning.

Dave Padfield is a lecturer at the University of Plymouth