No, I know about these round-the-houses ways of indicating ongoing action. We even have them in English, especially of the Synge dialect sort: "He is over beyant in Dingle an' he at the drinkin'" sort of Paddywhackery.
Where the original question was starting from:
In the three main languages historically sharing the British Isles (I'm counting the Gaelic dialects as one, and not counting Latin or French), two seem to have had this progressive 'I am doing' construction as the main present tense form. English adopted it later, though I don't know when it arrived in writing, or if there was pedantic resistance to it.

It seems to be uncommonly used, as a special effect only, in most other European languages.
Some time ago, on the Britarch list, there was a discussion concerning the apparent poverty of words in English from the ancient British language (palaeo-Welsh), and this was used as an argument for large scale replacement of the native population.
It occurred to me at the time that the structure of the progressive present tense could be an adoption from one of the Celtic languages, preserved by the ex-Celtic Anglo Saxon peasants, and ignored by the (aristocratic and conservative) AS literary language. The destruction of the literary elite by the Norman conquest allowed many (perhaps demotic) features to come through into writing- notably the collapse of gender, case inflexion, concordance etc.
But for the progressive present to be part of the package (how's that for AS alliteration?) timing is all. I can't find any examples of it in the few middle-English sources available to me (Gawain, Piers Plowman, riddles, Sir Orfeo, one or two more) but neither can I find when it DID come in. I sometimes suspect that the 'special' nature of writing prior to the invention of printing inhibited the use of forms thought to be ungrammatical- but that's not evidence.
So the question is: did this usage spring up spontaneously, was it adopted from another (higher status?) European language, was it adopted from (definitely low-status) Irish or Welsh, or did it rise from the underground of English dialect, the Brythonic language showing through the flourishing growth of English like a crop mark in a field?

Paul Burke

An interesting and thoughtful post Paul, thanks. Nice how these simple questions can make one scratch one's head. As I read what you wrote the idea that this was a remainder of the 'low-level' languages seemed the more likely one. Are there progressive forms in these languages, or traces of them?
Of course it could just have been England being Perfidious Albion again and that the English decided to get up the nose of the rest of the continent by doing things differently, as is their wont.