def count_words(sentence):
    sentence = sentence.lower()
    cleaned = ""
    for symbol in sentence:
        if symbol.isalnum() or symbol == "'":
          cleaned += symbol
        else:
            cleaned += " "

    counts = {}
    for word in cleaned.split():
        word = word.strip("'")
        if word:
            counts[word] = counts.get(word, 0) + 1
    return counts