How to explain the situation in French where an object pronoun needs to precede the predicate, while an object R-expression stands to the right of the predicate?
Here is an example:
a. Il le regarde. (He him sees.)
b. Il regarde Julie. (He sees Julie.)
(Tense is not considered here to make the sentences simpler)
Sentence (a) shows that the pronoun le precedes the verb. However, in sentence (b), the name Julie follows the verb.
I wonder how phrase structure grammar explains this phenomenon. Could somebody help me comprehend it?