I’m using church romanization and tone indications. I use a capital O to represent the ‘dotted’ O. I also put the shifted tones (bian4diao4) totallytika mentioned in square parentheses .
Female cha[7]-bO2
Male cha[7]-pO
In this basic pair, there is a phonemic difference and a tonal difference in the second syllable. In cha-bO2, bO begins with the soft, unaspirated, buzzed ‘b’ sound Omni mentioned. This sound is similar to the ‘b’ in ‘about’. The pO in cha-pO begins with an unaspirated b sound similar to the ‘p’ in ‘keep out’.
There is also a tonal difference. bO2 is a falling tone equivalent to the fourth tone in Mandarin while pO is a flat, level tone equivalent to the first tome in Mandarin. So far Omni and I are on the same page. I think he’s simplified the rest of discussion so that you do not despair. Here lie dragons.
cha[7]bO2-e5[3] female, girl, woman
cha[7]pO-e5[1] male, boy, man
These two are really tough. In this case, as Omni says, the bO2 and pO do not change tones. However the final e5 does change tones according to the 1-3-7 rule.
Under this rule, particles like e5 and a (in certain cases) change depending on the tone of the PREVIOUS syllable. If the previous syllable is first tone, the following particle changes to the first tone. If the previous syllable is second, third, fourth, or fifth tone, the following particle changes to the third tone. If the previous syllable is seventh or eighth tone, the following particle changes to the seventh tone.
In this case the e5 in cha[7]-bO2-e5[3] changes to the third tone because the preceding bO2 is second tone. The e5 in cha[7]-pO-e5[1] changes to the first tone because pO is in the first tone.
cha[7]-bO2[1]-gin2[1]-a2 girl
cha[7]-pO[7]-gin2[1]-a2 boy
This pair follows regular tone-change rules. All tones change except the tone on the final syllable a2. The regular tone changes are:
1->7
2->1
3->2
4->2
5->7
6[unused]
7->3
8->3
I find this pair the toughest thing I have learned in Taiwanese so far because it requires me not only to distinguish between the initial ‘b’ and ‘p’, but also because it requires complete knowledge of tone rules including the crucial 1-3-7 rule.
A tip: I find Taiwanese easier if I concentrate on identifying the syllables WITHOUT tone changes.