The word "quadru" can be spelled using the International Phonetic Alphabet transcription as /kwɒdruː/. The first two letters, "qu", represent a digraph which makes a /kw/ sound. The following letter, "a", is pronounced as /ɒ/. The letter "d" is pronounced as /d/, and the letter "r" is pronounced as /r/. The final letter, "u", is pronounced as /uː/. Despite the word being relatively short, its unique spelling highlights the importance of understanding phonetic transcriptions to accurately pronounce unfamiliar words.
Common prefixes in scientific words, signifying "four," “containing four parts".
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.