chore: fix small typo

diff --git a/units/src/amount/mod.rs b/units/src/amount/mod.rs
index d799b5ec..bc2e79c4 100644
--- a/units/src/amount/mod.rs
+++ b/units/src/amount/mod.rs
@@ -146,7 +146,7 @@ impl Denomination {
     }
 }
 
-/// These form are ambiguous and could have many meanings.  For example, M could denote Mega or Milli.
+/// These forms are ambiguous and could have many meanings.  For example, M could denote Mega or Milli.
 /// If any of these forms are used, an error type `PossiblyConfusingDenomination` is returned.
 const CONFUSING_FORMS: [&str; 6] = ["CBTC", "Cbtc", "MBTC", "Mbtc", "UBTC", "Ubtc"];