Need help with this problem

This first function translates normal words into "pirate speak"

def translate_pirate_word(word):
    if word == "my":
        return f"me"
    elif word == "you":
        return f"ye"
    elif word == "is":
        return f"be"
    elif word == "are":
        return f"be"
    elif word == "hello":
        return f"ahoy"
    elif word == "yes":
        return f"arr"
    elif word == "friend":
        return f"matey"
    elif word == "friends":
        return f"hearties"
    else:
        return f"{word}"

This function takes a sentence then translates "pirate words" into the ones applicable 

def translate_to_pirate(normal_sentence):
    normal_sentence += " "
    empty =""
    pirate_sentence = ""
    for char in normal_sentence:
        if char != " ":
            empty = empty + char
        else:
            pirate_sentence += translate_pirate_word(empty)
            empty =" "
    return pirate_sentence

When I run this function to test it it prints out " matey are" so it translates the first word but not the following words.

I have tested it with other things too like translate_to_pirate("yes hello") and it does the same thing and only translates the first word

print(translate_to_pirate("friend are "))

Any help is welcome

Thanks :)