The expression "hadst case" is not commonly used in modern English, but it is sometimes found in older texts. The word "hadst" is the second person singular past tense of the verb "have". It is spelled with the letters "h", "a", "d", "s", and "t". The IPA phonetic transcription for "hadst" is /hædst/. The "h" represents the voiceless glottal fricative, the "æ" represents the vowel sound in "cat", the "d" represents the voiced alveolar stop, the "s" represents the voiceless alveolar fricative, and the "t" represents the voiceless alveolar stop.