1. कुछ शब्द Singular तथा Plural में एक समान रहते हैं इन्हें Plural Form में नहीं बदला जा सकता
जैसे- Brace, cannon, cod, corps, hertz, fracas , means, mackerel, mathematics offspring, politics, pike salmon, series, swine, trout, yoke, deer , sheep, fish means, score, agenda, data etc
Examples;
Mathematics is an interesting subject.
His mathematics are weak.
The Wages Of Sin Is Death.
The Wages Of The Workers Have Been Raised.
I Saw A Sheep Grazing In The Field.
Sheep Are Sold Cheaper Than Goat.

2. Dozen, Score, Hundred, Thousand का प्रयोग Singular Number के रूप में होता है यदि इनका प्रयोग अंको के बाद किया गया हो लेकिन Dozens of eggs, Hundreds of people कहा जाता है
Examples-
I have bought five dozen bananas.
I have bought dozens of bananas.