How to spot English loanwords and Hanja words in a text?
While studying Japanese, it's very helpful that nearly all words of foreign origin are marked by using katakana (a syllabary separate from the usual mix of hiragana and Chinese characters) and words based on Chinese readings of characters are usually also recognizable by the absence of additional hiragana characters. While this graphical distinction of words of different etymological background is absent in modern Korean writing, it might be possible nevertheless to guess which words are of (say) English or Chinese origin, by looking at the occurring sound combinations and orthographic features. For example, strong consonants and syllables with two final consonants seem to occur only in native Korean vocabulary, while words ending in eu (e.g. 테니스) are commonly derived from Western words ending in a consonant. Any other heuristics?