Is it possible to achieve spoken fluency in a second language without being able to read it?

This question was sent in by Ian McGilloway and comes, in part, from a discussion he had on holiday where the local staff at a diving company in a small fishing village on an island spoke pretty good English with English accents but could barely read and write. He wondered how far they could take their range of language and if they would plateau out without the extra input from reading.

He thinks it possible to speak a second/foreign language fluently without being literate in it, but it would be considerably easier if you could read it. Largely because the range of vocabulary you’d be exposed to would be far greater. In particular, with languages which have different registers that depend on the social status of people in the group and so on.

In some cases language learners might learn to read a language only in transliteration if it’s written with a different alphabet or other writing system. This is especially true for Chinese and Japanese. They can achieve spoken fluency in such languages, I think, but might miss out on some literary aspects.

Have you learnt to speak any languages without learning to read them?

Or conversely have you learnt to read any languages without learning to speak them?