diff --git a/lectures/lec02.tex b/lectures/lec02.tex
index 8bca4fa..67bca4d 100644
--- a/lectures/lec02.tex
+++ b/lectures/lec02.tex
@@ -367,7 +367,7 @@ \subsection{Avoiding phishing: U2F (simplified)}
 \section{Biometrics}
 Biometrics are physical features like your fingerprints, your face, etc.
 They are very convenient to use for authentication, since you will not forget them and cannot easily lose them.
-Biometrics most useful when authenticating in person to a device, such as for phone unlock, or
+Biometrics are most useful when authenticating in person to a device, such as for phone unlock, or
 to grant a person access to a secure vault.
 In these settings, the device performing the authentication has a ``trusted input path''
 that can provide some assurance that a real human who owns that biometric is on the other end.