Proper spelling?

@jk123 The correct spellings are the ones with the "u". However, if we'd base it on actual usage, the ones without the "u" would be a lot more common. As a result, I don't think it really matters which one is used in regular, or even in some formal, communication. In textbooks though, I believe the correct spellings must be observed.The "u" is essential for syllabication purposes, which explains its presence. Yet, within a word, every time it is followed by "w", the sound of "u" naturally blends with the initial sound of "w". Thus, it may be viewed already as redundant, resulting in the tendency of writers to omit it.