Answer:
Here's a Python program that creates a copy of a given string with all occurrences of the letter 't' converted to uppercase:
def uppercase_t(string):
new_string = ""
for char in string:
if char == "t":
new_string += char.upper()
else:
new_string += char
return new_string
The function uppercase_t() accepts a string as input and creates a new string called new_string. It then loops through each character in the input string using a for loop. If the current character is the letter 't', the function converts it to uppercase using the upper() method and adds it to the new_string. Otherwise, it just adds the current character as is. Finally, the function returns the new_string.
Here's an example usage of the function:
>>> uppercase_t("test string")
'TesT sTring'
>>> uppercase_t("the quick brown fox jumps over the lazy dog")
'The quick brown fox jumps over The lazy dog'