If the first compound is Latin then the connecting vowel is an-i-, whereas if the first compound is Greek, the connecting vowel is an-o -.
2.
If the first compound is Latin then the connecting vowel is an-i-, whereas if the first compound is Greek, the connecting vowel is an-o -.
3.
When compound words are created, a connecting vowel is needed depending on the origin of the preceding word, regardless of the word that follows, unless the latter starts with a vowel in which case no connecting vowel is added.
4.
When compound words are created, a connecting vowel is needed depending on the origin of the preceding word, regardless of the word that follows, unless the latter starts with a vowel in which case no connecting vowel is added.
5.
In addition to this native English compounding, there is the " bound form ( connected by connecting vowels, which are most often "-i-" and "-o-" in Latin and Greek respectively ) and cannot stand alone.