Say you have a theoretical language which has verbs that are never inflected. If that verb appears, it will only appear in one form. Tense and such things are marked with particles that follow the verb.
Now imagine another language which is exactly the same except the particles are suffixes. The only real difference is that spaces have been removed. It seems like a very minor difference, and probably wouldn't even be noticeable when speaking.
However, it seems like the second language is more agglutinative and the first is more analytic. This seems weird considering how similar the languages are.
So is there really a meaningful difference between particles and affixes? Is the difference between analytic and agglutinative languages merely superficial? Or does it go deeper that putting extra spaces when writing?
It seems like the answer to that last question is yes, considering Chinese languages like Mandarin are usually written without spaces. So if the only thing that mattered for words were spaces, then Chinese would be considered polysynthetic, since it would have sentence spanning words. But it's not, and it doesn't. In fact, it's considered to be analytic. So it seems like to answer this question, it might be required to get into the deeper question of what even is a word?