O governo mudou a lei.

In Portuguese, it is very common to use the definite article with nouns, including institutions and governments.

So o governo means the government.

Leaving out the article would sound less natural in a basic sentence like this. In many cases, Portuguese uses articles more often than English does.

• o governo = the government
• um governo = a government

Here, o tells you we are talking about a specific government.

Mudou is the verb mudar in the third person singular of the preterite tense.

So:

• mudar = to change
• mudou = changed

In this sentence, mudou means changed in the simple past:

• O governo mudou a lei. = The government changed the law.

Mudou is the preterite, which is commonly used for a completed action in the past.

So O governo mudou a lei presents the change as a finished event:

• The government changed the law

Compare:

• mudou = changed, did change
• mudava = used to change / was changing
• tem mudado = has changed / has been changing

A learner often notices that Portuguese has several past forms. Here, mudou is the normal choice for a single completed action.

Because mudar is an -ar verb, and in the preterite, the ele/ela/você form ends in -ou.

Pattern:

• eu mudei = I changed
• você/ele/ela mudou = you/he/she changed
• nós mudamos = we changed
• eles/elas mudaram = they changed

Since o governo is grammatically third person singular, the sentence uses mudou.

A lei means the law.

Portuguese usually needs an article before a singular countable noun in a sentence like this. So:

• a lei = the law
• uma lei = a law

If you said just lei here, it would generally sound incomplete or unnatural in standard usage.

Yes, governo is a masculine noun, so it takes o:

• o governo

Lei is feminine, so it takes a:

• a lei

This is grammatical gender, which does not always match any real-world gender. Since government and law are things, the masculine/feminine distinction is just part of the noun grammar.

Yes. This sentence follows the very common subject + verb + object order:

• O governo = subject
• mudou = verb
• a lei = object

So it matches English very closely:

• The government changed the law.

That makes this a very straightforward sentence for English speakers.

In Brazilian Portuguese, mudou is pronounced approximately like moo-DOH, with the stress on the last syllable.

A rough guide:

• mu sounds like moo
• dou sounds roughly like doh

So:

• mudou ≈ moo-DOH

Also, the final -ou in Brazilian Portuguese often sounds like a clear oh sound.

Yes. Once o governo has already been mentioned and the meaning is clear, you can refer back to it with ele, because governo is grammatically masculine singular.

For example:

• O governo mudou a lei. Ele também anunciou novas medidas.
  = The government changed the law. It/He also announced new measures.

Even though English uses it for government, Portuguese uses ele because governo is a masculine noun.

Sometimes, yes, depending on context.

Governo most directly means government, but in real usage it can sometimes refer to an administration or ruling government, depending on what the speaker means.

So the core meaning is:

• o governo = the government

But in some contexts, a natural English translation could be:

• the administration changed the law

The exact English wording depends on context, even though the Portuguese sentence itself stays the same.

Yes, often it would.

• mudou = changed
• alterou = altered / changed / modified

So:

• O governo mudou a lei.
• O governo alterou a lei.

Both can work, but alterou may sound a bit more formal or more specific in legal or official contexts. Mudou is very common and general.

In this sentence, a lei usually means a specific law that the listener/reader can identify from context.

So the most natural reading is:

• the law

If you wanted to say a law, you would normally say:

• uma lei

So:

• O governo mudou a lei. = The government changed the law.
• O governo mudou uma lei. = The government changed a law.

The article makes that distinction clear.