I've been wanting to learn more about beijinghua and it's been more challenging than I expected.
I've heard that sh, ch, and zh, all turn to r in beijinghua. However, I've also heard some examples when it becomes h (非常 Fēicháng > Fēihang) or when it still remains as a voiceless sh (历史 Lìshǐ > Lìshh ) .
I've tried coming up with and summarising what I have found/heard below. Corrections would be greatly appreciated
AFTER TONE 1
1 or 2 becomes h: 花生豆 Huāshēng dòu > Huā heng dòu, 非常 Fēicháng > Fēihang
3 or 4 becomes r: 多少 Duōshǎo > Duōr, 出示 Chūshì, Chūr
AFTER TONE 2
1 becomes h or r?: 图书馆 Túshūguǎn > Túrguǎn or Túhuguǎn ?
What happens after 2 and 3?
4 becomes r: 还是 Háishì > Háir
AFTER TONE 3
1 and 2 remain or change?: 小车 Xiǎochē > Xiǎoch, BUT 老师 Lǎoshī > Lǎor?
3 and 4 become r: 把手 Bǎshǒu > Bǎr, 手指头 > Shǒuzhǐ tou, 把式 Bǎ shi > Bǎr
AFTER TONE 4
1 becomes sh: 钥匙 Yàochí > Yàoshh, 蜡烛 Làzhú > Làshh, BUT 为什么 Wèireme ?
2 becomes r: 派出所 Pàichūsuǒ > Pàirsuǒ, 不知道 Bù zhīdào > Bùrdào
3 and 4 does it become sh or r?: 历史 Lìshǐ > Lìshh BUT 报纸 Bàozhǐ > Bàor?, 算数 Suànshù > Suànshh BUT 但是 Dànshì > Dànr?