Some thoughts on Tok Pisin

Verbs only have 2 states with regards to person: 1st/2nd and 3rd. Example:

Mi lainim Tok Pisin
'I learn/am learning/learned Tok Pisin'

Yu lainim Tok Pisin
'You learn/are learning/learned Tok Pisin'

Em i lainim Tok Pisin
'He/she learns/is learning/learned Tok Pisin'

Note: Tense is implied via context. Also, the 3rd person singular pronoun is ungendered.

The difference, seems to be the presence of the particle i. The source would be gramaticalization and simplification of the phrase "Him, he learns". The /h/ is weak and drops out, leaving just the vowel /ee/, which in Pisin is written i. Since the "he" would have no place in 1st or 2nd person, it was never used, thus the difference in syntax.