I know that we can find phonemes by looking for minimal pairs. However, I cannot find a minimal pair for the schwa, on the one hand, and the vowel that usually appears on British English vowel charts with this symbol /3:/ Presumably there must be a minimal pair, since we have two separate phonemes. Can someone give me an example? The only real difference seems to be be vowel length since they occupy almost the same position on the vowel chart.
In addition to forward - foreword, there are:
- Upton /ˈʌptən/ and upturn /ˈʌptɜːn/
As @Janus said in a comment, you could create minimal pairs, as in:
- afterwards /ˈɑːftəwədz/ and after words /ɑːftəwɜːdz/