input: Write a function to convert a given list into a dictionary where each element from the list becomes a key in the dictionary and is assigned a corresponding string value. The string values should be based on the English word for the number corresponding to the key. If the list is empty, return an empty dictionary.
  
  assert convert_list_to_dict([1, 2, 3, 4])=={1: 'one', 2: 'two', 3: 'three', 4: 'four'}
  assert convert_list_to_dict([])=={}
  assert convert_list_to_dict([5, 6, 7, 8])=={5: 'five', 6: 'six', 7: 'seven', 8: 'eight'}
  assert convert_list_to_dict([10, 20, 30])=={10: 'ten', 20: 'twenty', 30: 'thirty'}
  assert convert_list_to_dict([0])=={0: 'zero'}
output: def convert_list_to_dict(lst):
      num_to_word = {
          0: 'zero', 1: 'one', 2: 'two', 3: 'three', 4: 'four',
          5: 'five', 6: 'six', 7: 'seven', 8: 'eight', 9: 'nine',
          10: 'ten', 20: 'twenty', 30: 'thirty'
      }
      return {num: num_to_word.get(num, '') for num in lst}