The word(s) "unsuccessful" appears 2 time(s) in 2 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) He said: My Lord! surely my bones are weakened and my head flares with hoariness, and, my Lord! I have never been unsuccessful in my prayer to Thee:

(سورة مريم, Maryam, Chapter #19, Verse #4)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) We have not revealed the Quran to you that you may be unsuccessful.

(سورة طه, Taa-Haa, Chapter #20, Verse #2)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)