Verifique o pH e o cloro.

Verifique is the imperative form of the verb verificar.

In this sentence, it is a command or instruction: Verifique o pH e o cloro.

More specifically, it is the command form used with você (and also the same form used for o senhor / a senhora in polite speech).

• você verifica = you check / you verify
• verifique! = check! / verify!

So this sounds like an instruction you might see in a manual, on a sign, or in technical directions.

In Brazilian Portuguese, verifique sounds neutral to formal.

It is the command form associated with você, which is very common in Brazil, but because verificar itself is a slightly more formal or technical verb than everyday olhar or checar, the whole sentence has an instructional tone.

It sounds natural in contexts like:

• manuals
• maintenance instructions
• pool care instructions
• lab or technical settings

If you were speaking very casually, you might also hear:

• Checa o pH e o cloro.
• Confira o pH e o cloro.

But Verifique o pH e o cloro is perfectly natural for written instructions.

Portuguese often leaves out the subject pronoun when it is understood from the verb form or from the situation.

So instead of saying:

• Você verifique o pH e o cloro.

Portuguese normally just says:

• Verifique o pH e o cloro.

In commands, omitting the subject is especially common. If you add você, it usually sounds more marked, emphatic, or unnatural in a simple instruction.

Because both pH and cloro are being treated as specific things that should be checked, and Portuguese commonly uses the definite article in cases where English may or may not use the.

So:

• o pH = the pH
• o cloro = the chlorine

This is very normal in Portuguese, especially in technical or practical instructions.

English might say:

• Check pH and chlorine or
• Check the pH and the chlorine

Portuguese strongly prefers the article here:

• Verifique o pH e o cloro.

In standard usage, people say o pH.

For a learner, the simplest thing is to memorize it as a fixed expression:

• o pH

Acronyms and symbols in Portuguese often take a grammatical gender by convention, and in real usage pH is masculine.

So you should say:

• o pH está alto
• verifique o pH

not:

• a pH

In Brazilian Portuguese, pH is usually pronounced letter by letter:

• pe agá

So the sentence would sound roughly like:

• Verifique o pe agá e o cloro.

This is different from English, where people often just say pee-eich.

Because verificar normally takes a direct object.

So you say:

• Verifique o pH.
• Verifique o cloro.

not:

• Verifique ao pH
• Verifique no pH

This is similar to English check the pH, where check also directly takes an object.

Yes, in many contexts you could.

• Verifique o pH e o cloro.
• Cheque o pH e o cloro.

Both can mean check the pH and chlorine.

The difference is mostly tone:

• verificar = a bit more formal, technical, or instructional
• checar = more everyday, more influenced by English check

In manuals, labels, and technical guidance, verificar is often preferred.

Literally, cloro is chlorine, but in a sentence like this it usually means the chlorine level or chlorine content, especially in contexts like:

• swimming pools
• water treatment
• cleaning systems

Portuguese often uses the substance name as a shortcut for the measurement connected to it.

So verifique o cloro naturally means something like:

• check the chlorine level
• test the chlorine

In standard grammar, with tu, the affirmative command would be:

• Verifica o pH e o cloro.

With você, it is:

• Verifique o pH e o cloro.

That said, in most of Brazil, você is much more common than tu, or local speech mixes forms in different ways. So for general Brazilian Portuguese, verifique is a very useful form to recognize in instructions and formal commands.

You are more likely to see it in written instructions or hear it in a technical/practical context than in casual conversation.

For example:

• on pool maintenance instructions
• on product packaging
• in a maintenance guide
• from a technician giving instructions

In casual speech, a Brazilian might choose something a little less formal, depending on the situation, such as:

• Dá uma olhada no pH e no cloro.
• Confere o pH e o cloro.
• Checa o pH e o cloro.

But the original sentence is completely natural and correct.