The spelling of the word "Tereska" may seem confusing to some, but it's actually quite straightforward when you use IPA phonetic transcription. The first syllable, "Ter," is pronounced as /tɛr/ with a short "e" sound like in "met." The second syllable, "es," is pronounced as /ɛs/ with a long "e" sound like in "meet." The final syllable, "ka," is pronounced as /kə/ with a schwa sound like in "about." So, to summarize, the correct spelling of "Tereska" is quite simply a phonetic representation of its pronunciation: /tɛrɛskə/.
The etymology of the word Tereska is unclear. The name Tereska is primarily considered a feminine given name in various cultures, but its specific origins are difficult to trace. It is possible that Tereska is a variant or diminutive form of other names such as Teresa or Theresa, which have Latin, Greek, or Spanish origins. However, without further information or context, it is challenging to determine the precise etymology of the word Tereska.