Translation:My grandmother does not run in February.
A native Brazilian speaker really needs to comment on this, but as a non-native speaker married to a Brazilian that hears more Portuguese spoken at home than English, I hear my boys talk to and refer to their grandmother.
To my ears, vó (grandmother) has a softer 'o' sound than vô (grandfather). In fact, vó almost seems to have a soft 'a' sound (think short vowel sound), whereas vô almost has hard 'o' sound (think long vowel sound).
In addition to the fact I'm not a native speaker, there is also the minor detail of my poor hearing. So, please take this with an extra grain of salt. However, I am able to distinguish between the two now, and the above explanation is how I distinguish them in my mind. Lastly, if you plug each one into Google Translate and click the microphone button, you can get a feel for the difference.
Actually, what he's referring to isn't the time-length of the vowel, but rather what we Americans typically learn in school as children. We learn to identify the "o" in "hot" as "short" and the "o" in "toe" as "long" (linguistically it's because these sounds used to actually differ from each other in time-length, before the "great vowel shift") -- so it more-or less matches your examples
As of the end of July shortened versions of Grandmother are not accepted TBF I only use one similar to the above "Gran" however if Avó vó & vovó are acceptable in BR or PT I suggest Nan, Nana, Gran, Grandma (nana like vovó is more common with neto pequeno ) while for male Avô & vô (if there are others I have not come across them as yet while learning ) could be Granddad, Grandpa, Gramps, grandfather, pops if I have understood the proposing / updating process for Duo each in this case female valid alternative would need to be reported as my response should have been accepted. I suggest some can from a pc where there are no ♡ <3 to be lost as on phones or tablets
I was corrected to "Minha Avó......" which is kind of ridiculous because I really cannot hear the "a" in "avó", but oh well.....
So I must ask: When is vó used as opposed to avó? Is it a question of formality? As in pai vs. papai, mae vs mamae?
(Sorry I didn't add the accents, I'm typing on a PC and haven't quite figured out how to insert special characters yet and I'm tired of cutting and pasting).
Is this really incorrect: "Minha avó não corre em fevereiro."? Other translation tools like it just fine. In this forum, when a learner asks if DuoLingo has an error, knowledgeable people should acknowledge this, here in the forum. I understand that the errors don't get fixed by DuoLingo, but it would be nice if a fluent speaker would clarify here in the forum. Okay, I just played the sound at the slow speed, and the speaker is saying "vó", not "avó". But at normal speed there is absolutely no difference in sound between "minha avó" and "minha vó". And they're both correct.