diff --git a/lib/thor/parser/options.rb b/lib/thor/parser/options.rb
index 497bcbb3..5d6a6fd7 100644
--- a/lib/thor/parser/options.rb
+++ b/lib/thor/parser/options.rb
@@ -144,7 +144,7 @@ def parse(args) # rubocop:disable Metrics/MethodLength
     def check_exclusive!
       opts = @assigns.keys
       # When option A and B are exclusive, if A and B are given at the same time,
-      # the diffrence of argument array size will decrease.
+      # the difference of argument array size will decrease.
       found = @exclusives.find{ |ex| (ex - opts).size < ex.size - 1 }
       if found
         names = names_to_switch_names(found & opts).map{|n| "'#{n}'"}
@@ -175,7 +175,7 @@ def check_unknown!
 
   protected
 
-    # Option names changes to swith name or human name
+    # Option names changes to switch name or human name
     def names_to_switch_names(names = [])
       @switches.map do |_, o|
         if names.include? o.name
diff --git a/spec/parser/options_spec.rb b/spec/parser/options_spec.rb
index 200a5d5f..ce1025f5 100644
--- a/spec/parser/options_spec.rb
+++ b/spec/parser/options_spec.rb
@@ -262,11 +262,11 @@ def remaining
                [["foo", "bar"], ["baz","qux"]])
       end
 
-      it "raises an error if exclusive argumets are given" do
+      it "raises an error if exclusive arguments are given" do
         expect{parse(%w[--foo --bar])}.to raise_error(Thor::ExclusiveArgumentError, "Found exclusive options '--foo', '--bar'")
       end
 
-      it "does not raise an error if exclusive argumets are not given" do
+      it "does not raise an error if exclusive arguments are not given" do
         expect{parse(%w[--foo --baz])}.not_to raise_error
       end
     end
@@ -277,7 +277,7 @@ def remaining
                [], [["foo", "bar"], ["baz","qux"]])
       end
 
-      it "raises an error if at least one of required argumet is not given" do
+      it "raises an error if at least one of required argument is not given" do
         expect{parse(%w[--baz])}.to raise_error(Thor::AtLeastOneRequiredArgumentError, "Not found at least one of required options '--foo', '--bar'")
       end
 
@@ -292,11 +292,11 @@ def remaining
                [["foo", "bar"], ["baz","qux"]])
       end
 
-      it "raises an error if exclusive argumets are given" do
+      it "raises an error if exclusive arguments are given" do
         expect{parse(%w[--foo --bar])}.to raise_error(Thor::ExclusiveArgumentError, "Found exclusive options '--foo', '--bar'")
       end
 
-      it "does not raise an error if exclusive argumets are not given" do
+      it "does not raise an error if exclusive arguments are not given" do
         expect{parse(%w[--foo --baz])}.not_to raise_error
       end
     end
@@ -307,7 +307,7 @@ def remaining
                [], [["foo", "bar"], ["baz","qux"]])
       end
 
-      it "raises an error if at least one of required argumet is not given" do
+      it "raises an error if at least one of required argument is not given" do
         expect{parse(%w[--baz])}.to raise_error(Thor::AtLeastOneRequiredArgumentError, "Not found at least one of required options '--foo', '--bar'")
       end
 
diff --git a/spec/thor_spec.rb b/spec/thor_spec.rb
index 6d03eb41..fe15d9be 100644
--- a/spec/thor_spec.rb
+++ b/spec/thor_spec.rb
@@ -581,7 +581,7 @@ def shell
         expect(content).not_to match(/Exclusive Options:/)
       end
 
-      it "prints class at least one of requred options" do
+      it "prints class at least one of required options" do
         content = capture(:stdout) { MyClassOptionScript.help(shell) }
         expect(content).to match(/Required At Least One:\n\s+--three\s+--four\n/)
       end