Pas je starý, je však stále platný.

Yes, pas can have more than one meaning in Czech, just like some English words do.

In this sentence, pas means passport. That is clear from the adjective platný (valid), because documents like passports, tickets, and IDs are commonly described as platný / neplatný (valid / invalid).

So although pas can mean other things in other contexts, here the surrounding words make passport the natural interpretation.

Pas is masculine inanimate.

You can tell from the adjective forms:

• starý
• platný

These are masculine singular nominative forms. If the noun were feminine, you would expect:

• stará
• platná

If it were neuter:

• staré
• platné

So the sentence structure shows that pas is masculine singular.

Because the sentence has two separate clauses, and each clause has its own verb:

1. Pas je starý = The passport is old
2. je však stále platný = however, it is still valid

In Czech, if you have two coordinated clauses like this, it is completely normal to repeat the verb. English does the same in a full version:

• The passport is old, but it is still valid.

So the second je is not redundant; it belongs to the second clause.

Czech often omits subject pronouns when they are already clear from context. This is very common.

In English, you usually need:

• it is still valid

But in Czech, once pas has already been mentioned, you do not need to repeat a pronoun like on (he/it, for masculine nouns). So Czech simply says:

• je však stále platný

The subject is understood to be pas.

If you did say on, it would usually sound more emphatic or contrastive than necessary here.

Here však means something like:

• however
• but
• nevertheless

It introduces a contrast:

• the passport is old
• however, it is still valid

So však connects the two ideas and shows that the second one contrasts with what you might expect from the first.

Both can express contrast, but they are not used in exactly the same way.

• ale usually corresponds directly to but
• však often feels a bit more like however / nevertheless

In many sentences they can be close in meaning:

• Pas je starý, ale stále platný.
• Pas je starý, je však stále platný.

The version with však is a little more formal or written in tone. It also often appears inside the clause rather than at the very beginning.

So for learners:

• use ale for a simple everyday but
• learn to recognize však as a slightly more literary or formal contrast word

This is a typical Czech word-order pattern.

Však is one of those words that often stands in an unstressed, non-initial position, frequently near the beginning of the clause but not necessarily as the first word. So:

• je však stále platný

sounds natural.

Czech word order is more flexible than English word order, but it is not random. Small connecting words like však often prefer certain positions.

You may also see other arrangements in real Czech, but this one is very normal and idiomatic.

Stále means still.

So:

• stále platný = still valid

It expresses continuation: despite being old, the passport continues to be valid.

A learner should notice that stále is an adverb, and here it modifies the adjective platný.

Because they agree with pas.

In Czech, adjectives must agree with the noun in:

• gender
• number
• case

Here the noun is:

• pas = masculine inanimate
• singular
• nominative

So the adjectives also appear in the masculine singular nominative form:

• starý
• platný

This is one of the most important grammar patterns in Czech: adjective-noun agreement.

Yes. Platný is the standard and very common word for valid when talking about documents, tickets, laws, contracts, and similar things.

Examples:

• platný pas = valid passport
• platná jízdenka = valid ticket
• platný občanský průkaz = valid ID card

Its opposite is:

• neplatný = invalid / no longer valid

So stále platný is a very natural phrase.

Yes, absolutely. That would be a very natural sentence too.

Compare:

• Pas je starý, ale stále platný.
• Pas je starý, je však stále platný.

The first is a bit simpler and more conversational. The second sounds slightly more formal or stylistically polished.

So both are correct; they just have a slightly different feel.

Because the sentence contains two coordinated clauses:

• Pas je starý
• je však stále platný

In Czech, as in English, clauses of this type are normally separated by a comma.

So the comma marks the pause and the contrast between the two parts of the sentence.