I don't know how to go about turning this into a dict

Hi there, pointers below

1. Create a dict to return word_dict ={}
2. l would use lower() after the split, just in case:
   

new_list = arg.split().lower()

1. you are on the right track with count

instances = new_list.count(item)

1. Update the dict with the item and instances

word_dict.update({item:instances})

Hope that helps

I would do the following:

Lowercase the entire string from the beginning

words = arg.lower().split()

Declare an empty dictionary to hold your word counts
You'll add words to the dictionary using word_dict[word] = value

word_dict = {}

Keep a running total of word counts
Unless you're supposed to use the count method I would just keep a running total. The reason being that the count method goes through the entire list every time you run it, so for "I do not like it Sam I Am" you'll run through the string 8 times with the count method or just 1 time keeping a running total.

All together now:

def word_count(string):
    words = string.lower().split()
    word_dict = {}

    for word in words:
        if word in word_dict:
            # Word in dict, add one to count
            word_dict[word] += 1
        else:
            # Word not in dict, add it and set it to 1
            word_dict[word] = 1

    return word_dict