For counting:
* Isa - This is the most common and general way to say "one."
For ordinal numbers:
* Una - This means "first."
Other variations:
* Iisa - This emphasizes that there is only one.
* Isang - This is used before a noun and can be translated as "a" or "one."
So, depending on the situation, you can use any of these words to express "one" in Tagalog.