May tagas ang tubo.

Here, may expresses existence or possession. In this pattern, it works like there is or has in English.

So May tagas ang tubo can be understood as:

• The pipe has a leak
• There is a leak in the pipe

Filipino often uses may instead of a separate verb like to have.

With may, a very common sentence pattern is:

May + thing that exists + ang/si phrase

So:

• May tagas ang tubo

This is the normal, natural order.

If you want to put ang tubo first, you usually need ay:

• Ang tubo ay may tagas

That version is also correct, but it sounds a bit more formal or more deliberately structured.
Ang tubo may tagas without ay is generally not the standard form.

Ang marks the topic of the sentence.

In this case, ang tubo is the thing being talked about: the pipe.
The sentence is saying something about that pipe, namely that it has a leak.

For English speakers, it can be helpful to think of ang tubo here as the pipe.

No. In this sentence, tagas is being used as a noun, meaning leak or leakage.

So the sentence is not literally using a verb meaning to leak. Instead, it uses the may construction:

• May tagas ang tubo = The pipe has a leak

That is different from a sentence that describes the action of leaking.

There is no separate word for is here, and none is needed.

Filipino often forms sentences without an English-style copula like is/are.
In this sentence, may already serves as the predicate, so May tagas ang tubo is complete by itself.

Yes. Ang tubo ay may tagas is correct.

The difference is mostly in style and focus:

• May tagas ang tubo = very natural, common, and straightforward
• Ang tubo ay may tagas = also correct, often a bit more formal or more emphatic on the pipe

Both mean the same basic thing.

Yes, and it is also natural.

There is a small difference in nuance:

• May tagas ang tubo
  Focuses on the pipe as the thing that has a leak.

• May tagas sa tubo
  Focuses more on the existence/location of the leak: there is a leak in the pipe.

In many everyday situations, the two are very close in meaning.

Yes. Tubo can mean different things depending on context. It can refer to:

• pipe / tube
• sugarcane
• profit
• other related meanings in some contexts

In May tagas ang tubo, the context makes tubo mean pipe or tube, because tagas strongly suggests something hollow that can leak.

They have the same core idea: there is / have.

In this sentence, may is the simplest and most natural form:

• May tagas ang tubo

You may also hear:

• Mayroong tagas ang tubo
• Merong tagas ang tubo

Those are possible, but may is the most common everyday choice here.

Filipino does not use articles in the same way English does.

So tagas by itself can correspond to:

• a leak
• the leak
• leakage

The exact English wording depends on context.
In this sentence, English usually uses a leak, but Filipino does not need a separate word for a.