I was just wondering if one were to segment Irish (by years into periods)

300-500
600-800
900-1100
1200-1600
1600-1850
1850-1950
1950-Now

what would eb the main featetures that would summ it up?

I'll get the ball rolling:

300-500 (loss of locative into dative; start of lention and eclipsis)

600-800 (rise of lention & eclipsis as morophological; weakening of nominative to dative)

900-1100 (verbal complexity reduction; Old Norse influence; less infixed pronouns)

1200-1600 (weaking and loss of neutral gender; in some dilects a loss of 'nuetral consonants'; Norman French influcnce; seperation from Socts Gaelic)

1600-1850 (Loss of nominative then the accusitive; English influence;)

1850-1950 (Weakening of Dative)

1950-Now (phonetic simplification; gramtical simplifiction; loss of dative and weaking of genitve)

Any other things of interest?