diff --git a/functions/reactWord.py b/functions/reactWord.py
index fc4b5fc..51f982a 100644
--- a/functions/reactWord.py
+++ b/functions/reactWord.py
@@ -1,13 +1,167 @@
 def check(content, earlier=[]):
+    # No arguments passed
     if len(content) < 1:
         return False, ["Controleer je argumenten."]
-    if any(not (x.isalpha() or x.isdigit() or x in ["#", "*", "!", "?"]) for x in content):
-        return False, ["Dit is geen geldig woord."]
-    if content[-1].isdigit() and len(content[-1]) > 10:
-        content[0] = "".join(x for x in content[:-1])
-    else:
-        content[0] = "".join(x for x in content)
 
+    # This command should work case insensitive
+    for i, word in enumerate(content):
+        content[i] = word.lower()
+
+    invalid_characters = []
+
+    # Check valid characters
+    for word in content:
+        for letter in word:
+            if letter not in allowedCharacters():
+                invalid_characters.append(letter)
+
+    # Get uniques
+    invalid_characters = list(set(invalid_characters))
+
+    # Invalid char was passed
+    if len(invalid_characters) == 1:
+        return False, ["**{}** is geen geldige letter.".format(invalid_characters[0])]
+
+    # Multiple invalid chars were passed
+    if len(invalid_characters) > 1:
+        return False, ["**{}** en **{}** zijn geen geldige letters.".format(
+            ", ".join(invalid_characters[:-1]), invalid_characters[-1]
+        )]
+
+    # Check if ID was passed or not, remove from list of words if so
+    # Also join everything into one word
+    if content[-1].isdigit() and len(content[-1]) > 10:
+        content[0] = "".join(content[:-1])
+    else:
+        content[0] = "".join(content)
+
+    # In case a space was passed using "a b", strip it out as well
+    content[0] = content[0].replace(" ", "")
+
+    doubles = getDoubles()
+
+    nums = getNumbers()
+
+    specials = getSpecialCharacters()
+
+    unidic = getUnicodeDict()
+
+    # Check for reactions that were already added earlier
+    for x in earlier:
+        # Check if reaction is a random reaction or a letter/number
+        if x in unidic.values():
+            word = ""
+            # Find the key used, remove it from the list of remaining available letters
+            for key in unidic:
+                if unidic[key] == x:
+                    word = key
+                    break
+
+            del unidic[word]
+
+            # Same thing for doubles
+            for k in list(doubles.keys()):
+                if word in doubles[k]:
+                    doubles[k].remove(word)
+                    if len(doubles[k]) == 0:
+                        del doubles[k]
+                    break
+
+            # Same thing for numbers
+            for k in list(nums.keys()):
+                if nums[k] == word:
+                    del nums[k]
+
+            # Same thing for special characters
+            for k in list(specials.keys()):
+                if word in specials[k]:
+                    specials[k].remove(word)
+                    if len(specials[k]) == 0:
+                        del specials[k]
+
+    # Check if earlier letters made this reaction impossible
+    for letter in content[0]:
+        c = content[0].count(letter)
+
+        # If a letter was added twice, but there is only one, that's an issue
+        if c != 1 and letter not in doubles:
+            return False, ["Er zijn niet genoeg **{}**'s om dit woord te reacten.".format(letter)]
+        elif c > 1 and letter in doubles and len(doubles[letter]) < c:
+            return False, ["Er zijn niet genoeg **{}**'s om dit woord te reacten.".format(letter)]
+
+    # Array of emoji's
+    arr = []
+
+    # Start checking every character
+    for letter in content[0]:
+        # Letters
+        if letter.isalpha():
+            # Check if this letter has not been added yet
+            if "regional_indicator_{}".format(letter) in unidic and unidic["regional_indicator_{}".format(letter)] not in arr:
+                arr.append(unidic["regional_indicator_{}".format(letter)])
+
+                # Remove this letter as an option from the list of doubles
+                if letter in doubles:
+                    doubles[letter] = doubles[letter][1:]
+
+            # Letter has been added before, but there's a double for it
+            elif letter in doubles:
+                if len(doubles[letter]) == 0:
+                    return False, ["Er zijn niet genoeg **{}**'s om dit woord te reacten.".format(letter)]
+
+                # Remove the number-equivalent from nums if it is used as a substitute here
+                arr.append(unidic[doubles[letter][0]])
+                if doubles[letter][0] in nums.values():
+                    for k in nums:
+                        if nums[k] == doubles[letter][0]:
+                            del nums[k]
+                            break
+
+                # Remove this character from the list of available doubles
+                doubles[letter] = doubles[letter][1:]
+
+                # Remove from the dictionary of doubles if the last double was used
+                if len(doubles[letter]) == 0:
+                    del doubles[letter]
+            else:
+                return False, ["Er zijn niet genoeg **{}**'s om dit woord te reacten.".format(letter)]
+        # Special characteres
+        elif letter in specials:
+            # No more options
+            if len(specials[letter]) == 0:
+                return False, ["Er zijn niet genoeg **{}**'s om dit woord te reacten.".format(letter)]
+
+            # Add it to the array & remove from the list of options
+            arr.append(unidic[specials[letter][0]])
+            specials[letter].pop(0)
+
+            if len(specials[letter]) == 0:
+                del specials[letter]
+        # Number
+        else:
+            # Number was used before as a double for a letter
+            if letter not in nums:
+                return False, ["Er zijn niet genoeg **{}**'s om dit woord te reacten.".format(letter)]
+
+            arr.append(unidic[nums[letter]])
+
+            # Add this emoji to the array, remove it as a double everywhere
+            for x in doubles:
+                # Remove this number as a substitute if it is used anywhere
+                if nums[letter] == doubles[x][-1]:
+                    doubles[x] = doubles[x][:-1]
+                    if len(doubles[x]) == 0:
+                        del doubles[x]
+                    break
+    return True, arr
+
+
+def allowedCharacters():
+    return ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u',
+            'v', 'w', 'x', 'y', 'z', "!", "?", "#", "*", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]
+
+
+def getDoubles():
     doubles = {
         "a": ["regional_indicator_a", "a", "four"],
         "b": ["regional_indicator_b", "b"],
@@ -22,6 +176,10 @@ def check(content, earlier=[]):
         "?": ["question", "grey_question"]
     }
 
+    return doubles
+
+
+def getNumbers():
     nums = {
         "0": "zero",
         "1": "one",
@@ -35,6 +193,10 @@ def check(content, earlier=[]):
         "9": "nine"
     }
 
+    return nums
+
+
+def getSpecialCharacters():
     specials = {
         "?": ["question", "grey_question"],
         "!": ["exclamation", "grey_exclamation"],
@@ -42,6 +204,10 @@ def check(content, earlier=[]):
         "#": ["hash"]
     }
 
+    return specials
+
+
+def getUnicodeDict():
     unidic = {
         "regional_indicator_a": "🇦",
         "regional_indicator_b": "🇧",
@@ -93,74 +259,4 @@ def check(content, earlier=[]):
         "asterisk": "*️⃣"
     }
 
-    for x in earlier:
-        if x in unidic.values():
-            word = ""
-            for key in unidic:
-                if unidic[key] == x:
-                    word = key
-                    break
-            del unidic[word]
-            for k in list(doubles.keys()):
-                if word in doubles[k]:
-                    doubles[k].remove(word)
-                    if len(doubles[k]) == 0:
-                        del doubles[k]
-                    break
-            for k in list(nums.keys()):
-                if nums[k] == word:
-                    del nums[k]
-            for k in list(specials.keys()):
-                if word in specials[k]:
-                    specials[k].remove(word)
-                    if len(specials[k]) == 0:
-                        del specials[k]
-
-    for letter in content[0]:
-        c = content[0].count(letter)
-        if c != 1 and letter not in doubles:
-            return False, ["Dit is geen geldig woord."]
-        elif c > 1 and letter in doubles and len(doubles[letter]) < c:
-            return False, ["Dit is geen geldig woord."]
-
-    arr = []
-    for letter in content[0]:
-        if letter.isalpha():
-            if "regional_indicator_{}".format(letter) in unidic and unidic["regional_indicator_{}".format(letter)] not in arr:
-                arr.append(unidic["regional_indicator_{}".format(letter)])
-                if letter in doubles:
-                    doubles[letter] = doubles[letter][1:]
-            elif letter in doubles:
-                if len(doubles[letter]) == 0:
-                    return False, ["Dit is geen geldig woord."]
-                # Remove the number-equivalent from nums if it is used as a substitute here
-                arr.append(unidic[doubles[letter][0]])
-                if doubles[letter][0] in nums.values():
-                    for k in nums:
-                        if nums[k] == doubles[letter][0]:
-                            del nums[k]
-                            break
-                doubles[letter] = doubles[letter][1:]
-                if len(doubles[letter]) == 0:
-                    del doubles[letter]
-            else:
-                return False, ["Dit is geen geldig woord."]
-        elif letter in specials:
-            if len(specials[letter]) == 0:
-                return False, ["Dit is geen geldig woord."]
-            arr.append(unidic[specials[letter][0]])
-            specials[letter].pop(0)
-            if len(specials[letter]) == 0:
-                del specials[letter]
-        else:
-            if letter not in nums:
-                return False, ["Dit is geen geldig woord."]
-            arr.append(unidic[nums[letter]])
-            for x in doubles:
-                # Remove this number as a substitute if it is used anywhere
-                if nums[letter] == doubles[x][-1]:
-                    doubles[x] = doubles[x][:-1]
-                    if len(doubles[x]) == 0:
-                        del doubles[x]
-                    break
-    return True, arr
+    return unidic
\ No newline at end of file