Is Tagalog a tonal language?

No. There are no tones, and nothing in Tagalog works like Mandarin or Vietnamese. There is a different thing that catches people, and being told it is not tonal is what lets it catch them.

What tonal actually means

In a tonal language the pitch you say a syllable on is part of the word, the way a consonant is. Mandarin ma is four different words depending on the pitch contour. Tagalog does nothing like this. Pitch in Tagalog does what it does in English: it carries emotion and marks questions, and it never changes which word you just said.

What does change meaning

Stress. Which syllable you lean on is part of the word, and moving it can produce a different word entirely. The classic pair:

• BÚ-hay, stress on the first syllable, means life.
• bu-HÁY, stress on the second, means alive.

Same five letters, written identically in ordinary Tagalog. Only the stress tells them apart, and ordinary spelling does not mark it.

There is also a final glottal stop that behaves the same way, a small catch in the throat at the end of a word that dictionaries mark and everyday writing does not. Both are covered, with the pairs laid out, on the pronunciation page.

Why this matters more than it sounds

Learners are told early that Tagalog is not tonal, hear that as pronunciation is not going to be a problem, and stop paying attention to it. Then they spend a year putting the stress on the wrong syllable and being gently not understood.

The practical fix is to learn stress as part of the word from the start, the way you would learn gender in Spanish: not as a rule to apply later but as part of what the word is.