How to book a student for lessons on the phone; when they don’t speak English

I was given a telephone number yesterday, of a Spanish gentleman who wanted English lessons.
This happens frequently but usually, the student speaks some English.
This student spoke no English apart from ‘Hello’.
I was pleasantly surprised then when after about 3 minutes we managed to have enough conversation for me to fix some lessons and make him understand what I intended to do.
Basically, he could understand most of my English and I understood most of his Spanish.
Now, I don’t speak Spanish but its amazing what you can learn from a few noises and the odd word you do recognise!