These are all unsettled, controversial ideas in toki pona.
1) kule lon palisa li pona tawa mi.
2) kule pi lon palisa li pona tawa mi.
Prepositional phrases as modifiers. These are most obvious when they appear in the subject. When they appear at the end of a sentence, then you could always argue that the phrase modifies the whole sentence or what ever the reader thinks makes sense. Almost no one does 2). I plan to write the parser to treat prepositional phrases as exchangeable with any tail, single word modifier (i.e. they are modifiers that come last)
1) ni li lon insa poka.
2) ni li lon insa poka suli.
3) ni li lon insa pi poka suli.
4) jan li tawa en tan ma suli.
Complex prepositions. People act like they can be joined, and’ed and or’ed. Some argue that the tail of a complex preposition is actual a noun, but then no on adds the pi for it’s modifiers, like in 3). And in 4) it is impossible to not look at it as a complex preposition. I plan to parse preps as potentially complex as in 2) and 3).
1) 543 = 5 (hundred) 4 (tens) 3 (ones)
A decimal system is ten digits and some of the place names, for example, a place name every three places. The choice of words isn’t so important (words for commonly measured, e.g. tenpo or approximate values, suli, mute, lili are bad choices), I plan to implement numbers as parameterizable templates.
1) jan li toki e kalama Wakawaka.
2) jan li toki e Wakawaka.
3) mi kute e Tinton li pini lape.
4) soweli li Mijawu li Mijawu.
Onomatopoeia is so rare that the particular answer should not matter much. Forcing these to be proper modifiers sort of works, except in #5, it pedantic to make such an exclamation a modifier and in 2) it probably redundant to mention again that this is a sound, human sound, or animal sound. (kalama, nimi, mu) These should be allowed to stand bare. But possibly punctuated to distinguish from accidental unheaded proper modifiers.
1) jan li kepeken ilo kepeken soweli.
2) jan li kepeken ilo en soweli.
toki pona has these things that look like chains linked by particles. Sometimes the pattern seems to fight against recursive patterns, sometimes it seems to give up and just do recursion. For example, x en y en z can be read as an unordered list of elements. This is a very simple data structure, it fits with the design goals of a simple languages. a pi b c en a2 pi b2 c2 is something a of a tree structure at least. There are chains joined by chains. The prepositional phrases are odd balls because if you string them together, the particle is … blank, e.g. jan li sama soweli kepeken ilo. The chain of prep phrases either can be analyzed as having a particle with six forms, or a blank particle and the prepositional phrases is headed, or possibly conjunctions are ordinary chains. People seem to use 2) above, i.e. prepositional phrases are not chains like en, or pi. Anyhow, 1) and 2) are semantically equal and there isn’t a compelling reason to make 2) illegal– for one it makes texts clunkier, implies that a string of prep phrases should group together, e.g. sama A sama B kepeken X kepeken Y. I sort of want to make sure you can treat prepositional phrases as chains (it’s sort of elegant to treat all the phrases as the same datastructure), but won’t write my parser to expect them to be treated as chains.