If you hold the same visa non o single entry three years no breaks. Wp 3 years 40,000 thb a month no breaks. You can then apply with no pr for Thai citizenship. The law changed 2009 without wp it’s possible but need pr first I think around 10 years. There is also points you have to accumulate
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you need age what job you do and level of thai that sort of thing but from my understanding possible with limited thai but need to score the points in other ways. Good luck!