This one's been bugging me for a while.
In the UK and US there are many words we spell differently. A lot of these are (medical) words with double vowels eg:
oesophagus - esophagus
f
oetus - fetus
medi
aeval - medieval
h
aemoglobin - hemoglobin
This is mostly a complete pain when I have to search US databases for medical information and remember to spell words differently.
I'd like to know the name of what I'm angry at. I don't think they're 'diphthongs' - or at least that's not specific enough, as 'ou' in 'loud' is a diphthong - it's any two vowels making one sound. My problem is usually 'ae' or 'oe', and when you see them written the letters are often squashed together (unlike 'loud').
So what's the word for what causes my problems?