For a necktie:
* Tai: This is the most common word for a necktie.
For a tie (as in a tie game):
* Sare: This word means "draw" or "tie" in a competition.
For tying something together:
* Kufunga: This is the verb for "to tie" or "to bind."
* Kufunga kwa kamba: This specifically means "to tie with a rope" or "to bind with a rope."
The best way to know which word to use is to consider the context of the sentence.