a = ['I own 1/2 bottle', 'Give me 3/4 of the profit']
b = {'1/2': 'half', '1/4': 'quarter', '3/4': 'three quarters'}

def replace(x):
    for what, new in list(b.items()):
        x = x.replace(what, new)
return x
print(list(map(replace, a)))
Применение словаря замен строк к списку строк