A weak position, syntactically, is one in which a word -for instance a noun- is modified by something, such as a preposition; and as such, its meaning is not entirely reliant upon its own inflection (in the case of syntactical languages).

Such a situation is readily apparent in languages with strong declinating tendencies. For instance in Latin, a preposition would have been followed by a noun which would have been in a certain case (depending upon the preposition and its intent). As the various vulgar Latin dialects evolved into the Romance languages, such declinations became redundant to the common speaker and were dropped in favor of the more simple attachment of prepositions. Thus, a prepositional phrase rendered as 'preposition + noun-in-case' could now be rendered as simply 'preposition + noun'.

This was written by an undergraduate student of history and classics. It is not scholarly, but intended as an initial interpretation of 'weak position' to be amended by those with whom more advanced comprehension resides.

Grammar