diff --git a/classes/File.php b/classes/File.php
index 18ad828925..407fd32114 100644
--- a/classes/File.php
+++ b/classes/File.php
@@ -140,7 +140,7 @@ class File extends Memcached_DataObject
                     $redir_data = array();
                 } else {
                     // TRANS: Server exception thrown when a URL cannot be processed.
-                    throw new ServerException(_("Cannot process URL '$given_url'"));
+                    throw new ServerException(sprintf(_("Cannot process URL '%s'"), $given_url));
                 }
                 // TODO: max field length
                 if ($redir_url === $given_url || strlen($redir_url) > 255 || !$followRedirects) {
diff --git a/classes/Notice.php b/classes/Notice.php
index 12467c8501..3297c7a59e 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -1094,8 +1094,8 @@ class Notice extends Memcached_DataObject
                 if (!$id) {
                     common_log_db_error($reply, 'INSERT', __FILE__);
                     // TRANS: Server exception thrown when a reply cannot be saved.
-                    // TRANS: First arg is a notice ID, second ID is the ID of the mentioned user.
-                    throw new ServerException(_("Couldn't save reply for {$this->id}, {$mentioned->id}"));
+                    // TRANS: %1$d is a notice ID, %2$d is the ID of the mentioned user.
+                    throw new ServerException(sprintf(_("Could not save reply for %1$d, %2$d."), $this->id, $mentioned->id));
                 } else {
                     $replied[$mentioned->id] = 1;
                     self::blow('reply:stream:%d', $mentioned->id);
diff --git a/classes/Profile.php b/classes/Profile.php
index ae6a376021..3b1e54c4d2 100644
--- a/classes/Profile.php
+++ b/classes/Profile.php
@@ -736,8 +736,8 @@ class Profile extends Memcached_DataObject
 
         if (empty($role)) {
             // TRANS: Exception thrown when trying to revoke an existing role for a user that does not exist.
-            // TRANS: %1$s is the role name, %2$s is the user ID.
-            throw new Exception(sprintf(_('Cannot revoke role "%s" for user #%2$s; does not exist.'),$name, $this->id));
+            // TRANS: %1$s is the role name, %2$s is the user ID (number).
+            throw new Exception(sprintf(_('Cannot revoke role "%1$s" for user #%2$d; does not exist.'),$name, $this->id));
         }
 
         $result = $role->delete();
@@ -745,8 +745,8 @@ class Profile extends Memcached_DataObject
         if (!$result) {
             common_log_db_error($role, 'DELETE', __FILE__);
             // TRANS: Exception thrown when trying to revoke a role for a user with a failing database query.
-            // TRANS: %1$s is the role name, %2$s is the user ID.
-            throw new Exception(sprintf(_('Cannot revoke role "%1$s" for user #%2$s; database error.'),$name, $this->id));
+            // TRANS: %1$s is the role name, %2$s is the user ID (number).
+            throw new Exception(sprintf(_('Cannot revoke role "%1$s" for user #%2$d; database error.'),$name, $this->id));
         }
 
         return true;