diff --git a/exercises/practice/flower-field/.meta/tests.toml b/exercises/practice/flower-field/.meta/tests.toml
index c2b24fd..965ba8f 100644
--- a/exercises/practice/flower-field/.meta/tests.toml
+++ b/exercises/practice/flower-field/.meta/tests.toml
@@ -44,3 +44,6 @@ description = "cross"
 
 [dd9d4ca8-9e68-4f78-a677-a2a70fd7a7b8]
 description = "large garden"
+
+[6e4ac13a-3e43-4728-a2e3-3551d4b1a996]
+description = "multiple adjacent flowers"
diff --git a/exercises/practice/flower-field/flower_field.vader b/exercises/practice/flower-field/flower_field.vader
index c3047b8..5c23eb1 100644
--- a/exercises/practice/flower-field/flower_field.vader
+++ b/exercises/practice/flower-field/flower_field.vader
@@ -123,3 +123,8 @@ Execute (large garden):
   \ '1*22*2',
   \ '111111']
   AssertEqual g:expected, Annotate(g:garden)
+
+Execute (multiple adjacent flowers):
+  let g:garden = [' ** ']
+  let g:expected = ['1**1']
+  AssertEqual g:expected, Annotate(g:garden)
diff --git a/exercises/practice/isbn-verifier/.meta/tests.toml b/exercises/practice/isbn-verifier/.meta/tests.toml
index 6d5a845..17e18d4 100644
--- a/exercises/practice/isbn-verifier/.meta/tests.toml
+++ b/exercises/practice/isbn-verifier/.meta/tests.toml
@@ -30,6 +30,12 @@ description = "invalid character in isbn is not treated as zero"
 [28025280-2c39-4092-9719-f3234b89c627]
 description = "X is only valid as a check digit"
 
+[8005b57f-f194-44ee-88d2-a77ac4142591]
+description = "only one check digit is allowed"
+
+[fdb14c99-4cf8-43c5-b06d-eb1638eff343]
+description = "X is not substituted by the value 10"
+
 [f6294e61-7e79-46b3-977b-f48789a4945b]
 description = "valid isbn without separating dashes"
 
diff --git a/exercises/practice/isbn-verifier/isbn_verifier.vader b/exercises/practice/isbn-verifier/isbn_verifier.vader
index c19cdfe..e6379c0 100644
--- a/exercises/practice/isbn-verifier/isbn_verifier.vader
+++ b/exercises/practice/isbn-verifier/isbn_verifier.vader
@@ -19,6 +19,12 @@ Execute (invalid character in isbn is not treated as zero):
 Execute (X is only valid as a check digit):
   Assert !IsValid("3-598-2X507-9")
 
+Execute (only one check digit is allowed):
+  Assert !IsValid("3-598-21508-96")
+
+Execute (X is not substituted by the value 10):
+  Assert !IsValid("3-598-2X507-5")
+
 Execute (valid isbn without separating dashes):
   Assert IsValid("3598215088")
 
diff --git a/exercises/practice/line-up/.docs/instructions.md b/exercises/practice/line-up/.docs/instructions.md
index fb41d4c..9e686ec 100644
--- a/exercises/practice/line-up/.docs/instructions.md
+++ b/exercises/practice/line-up/.docs/instructions.md
@@ -5,9 +5,9 @@ Yaʻqūb expects to use numbers from 1 up to 999.
 
 Rules:
 
-- Numbers ending in 1 (except for 11) → `"st"`
-- Numbers ending in 2 (except for 12) → `"nd"`
-- Numbers ending in 3 (except for 13) → `"rd"`
+- Numbers ending in 1 (unless ending in 11) → `"st"`
+- Numbers ending in 2 (unless ending in 12) → `"nd"`
+- Numbers ending in 3 (unless ending in 13) → `"rd"`
 - All other numbers → `"th"`
 
 Examples: