I've searched this site for questions containing both thirteen and thirty, fourteen and forty, etc. up until I found this question about seventy. Most of the comments seem to be about using "sevenee" to emphasize 70 and using "steventeen" (with emphasis) to indicate 17. However this doesn't work for other numbers like 30 which would turn into something like "thurry".
The top answer on that question is this:
When speaking, you can distinguish between them more easily by stressing a different syllable:
- 17 = sev en TEEN
- 70 = SEV en tee
Is this the common practice? It doesn't seem to remove any ambiguity if you don't already know of the practice, but since it is the top voted answer I guess it might be the way to go.
In another, unrelated question I found this relevant remark in an answer:
Sometimes, it is helpful to read numbers digit by digit for clarity. For example, "fifteen" and "fifty" sound alike, so in aviation, such numbers are spoken as "one-five" and "five-zero", respectively; 1500 is "one-five-hundred".
But doing that in informal conversation? You would sound weird, and you probably wouldn't be understood. You could say it redundantly "fifteen (that's one-five)".
Which makes more sense to me as a non-native speaker. I'm assuming that even with a perfect pronunciation (which I don't think I have), there are still going to be cases where background noise (mainly when communicating with someone not next to you) or audio quality will cause it to become unclear anyway, but I might be wrong in that.
What's the way to go about this, keeping in mind that:
- I'll talk with a lot of non-native speakers who might not be used to some common practice; and
- still wanting to be clear (and not sounding silly or condescending) to native speakers?
Should I use different approaches for different numbers, like "sevenee" for 70 and "thirty like three-oh" for 30? What about other numbers?
Best Answer
"Thirteen" has primary stress on its second syllable and secondary stress on its first syllable -- that is "th2irt1een", using a notation similar to that of The Sound Pattern of English. "Thirty" has primary stress on its first syllable, but no stress on its second syllable: "th1irty". And similarly, "f2ourt1een" and "f1orty".
The stress, or lack of stress, conditions some common phonetic changes in casual pronunciation. A "t" after a vowel, a glide, or "r" and before an unstressed vowel can change to a flap, sometimes written "D", so we can get "th1irDy" and "f1orDy", but because of the stress on the following vowel, this does not affect the "t" of "th2irt1een" and "f2ourt1een".
At a even more casual level, the flap "D" can be lost, giving "th1iry" and "f1ory".
The example "s1eventy" is similar, but has extra complications. The second "e" becomes a nasal vowel "e~" under the influence of the following "n", then the "n" may be lost before "t", giving "s1eve~ty". Now, the "t" is after the vowel "e~" and before the unstressed vowel "y", so it can be flapped, giving "s1eve~Dy", then (if things get this far), the "D" is changed to a nasal flap "N" because of the preceding nasal vowel, giving "s1eve~Ny". Like oral flap "D", at a more casual level of speech, the nasal flap can be lost, giving "s1eve~y".
For other numbers, well, it just depends. It's not terribly complicated, but there is no single simple rule that will tell you what pronunciations you will find in American English.