Why does sign rhyme with fine and not end in a hard /g/? Because English has a clean pattern: when a word ends in -IGN or -EIGN, the G is silent, and the vowel before it grows long.
This single rule fixes a long list of words that learners often mispronounce, and it comes with an elegant twist worth knowing.
The Rule
In a final -IGN, the G is silent and the I says its long name /aɪ/: sign, design, resign, assign, align, malign, benign, campaign all end in the sound "-ine" (like mine). In a final -EIGN, the G is silent and the letters usually give /eɪ/: reign, feign, deign rhyme with rain. The GN spelling comes from Latin and French roots, where the G was once pronounced. In modern English the G quietly disappears at the end of a word.
Practice Words
The Twist: When the G Wakes Up
Add a suffix that pulls the G into a new syllable, and it becomes pronounced again, often with a short vowel. Compare sign /saɪn/ with sig-nal and sig-nature; design with des-ig-nate; resign with res-ig-nation; malign with ma-lig-nant; benign with be-nig-nant. The G was never truly gone; it just needed a vowel on its right to speak. Note the unstressed exception foreign and sovereign, where -EIGN reduces to /ən/ rather than /eɪn/.
Quick Tip
Ask one question: is the GN at the very end of the word? If yes, the G is silent and the vowel is long (sign, reign). If a suffix follows and splits G into a new syllable (sig-nature), pronounce it.