THEORY: Question: Bound Morphemes

I have a question. (Perhaps a stupid one).

In English, some bound morphemes are written as affixes, but others=20
are written as seperate words (like the articles 'a' and 'the'). But=20
aren't all bound morphemes in English (including the articles) really=20
affixes? If not, what rule states that they should be written=20
separately?

I'm asking because I have stumbled onto another problem with my=20
transcription of Boreanesian. I'm not sure whether to write the=20
determiners seperately (like English articles even though they are=20
bound morphemes) or as prefixes (because they are bound).

Thanks,
-kristian- 8)