In some languages, words are marked for more things than in others.
This affects what information must be included in a sentence or passage. For example, someone saying "Do you want to come along with us?" in Hebrew must mark the first or second word for gender and number (of the "you"), whereas in English the entire sentence can be said without any notice taken of gender or number.
It also affects how soon information must be included in a sentence or passage. For example, someone saying "I had two kittens" in English can leave the number (plural) of kittens out until he gets to the predicate; thus, when he starts the sentence, he need not even know what it is that he had: that comes later on in the sentence. In Hebrew, it's there-were to-me two kittens, so the speaker must know, as soon as he starts the sentence, what he's referring to at the end of it (or their number, anyway).
One can theorize that, in languages that make you plan your sentences ahead more (because more words are marked for more things and must agree), the speakers are in general more likely to have their words ready before speaking. That might manifest itself in reduced midspeech or increased prespeech usage of words like "um".
Has anyone researched correlation between markedness/agreement of words in a language and any other measure of having one's words ready before speaking? What has been found?
I am largely untrained in linguistics, so excuse my ignorance and, in particular, the imprecision or misapplication of any terms of art that I may use. I'd appreciate any edits that correct misuse of words, especially in the tags.