Internet-related prefixes as a cultural reference to the rising popularity at that time of the prefix in product names. The word "virtual" is used in a similar way to the prefixes above, but it is an adjective instead of a prefix. For example, it is used in the terms "virtual reality", "virtual world", and "virtual sex". These prefixes are productive. Michael Quinion notes that most of these formations are nonce words that will never be seen again. He writes that new terms such as "e-health" are unneeded; in this case "telemedicine" already exists to describe the application of telecommunications to medicine. He
English words of Greek origin to recognize words of Greek origin, and give hints as to their pronunciation and inflection. Some romanizations are not completely standard. The Ancient Greek diphthongs and may be spelled in three different ways in English: the digraphs "ae" and "oe"; the ligatures "æ" and "œ"; and the simple letter "e". The ligatures have largely fallen out of use worldwide; the digraphs are uncommon in American usage, but remain common in British usage. The spelling depends mostly on the variety of English, not on the particular word. Examples are: "encyclopaedia" / "encyclopædia" / "encyclopedia", "haemoglobin" / "hæmoglobin" / "hemoglobin", "oedema" /