It's a very common word used in various contexts.
Here are some examples:
* Lahat ng tao - All people
* Lahat ng bagay - Everything
* Lahat tayo - All of us
* Lahat ng oras - All the time
It's important to remember that Tagalog is a language with a wide variety of dialects and regional variations. While "lahat" is the most common and understood word for "all" throughout the Philippines, there may be some regional variations in pronunciation or usage.