Learn Hardcore Polish: Mój paszport jest lżejszy niż mój bagaż.

Comparative adjectives in Polish agree with the noun’s gender, number, and case. To form lżejszy (‘lighter’), start from lekki (‘light’): • Adjectives ending in -ki/-gi remove that ending and add -szy: lekki → lek- + szy.
• The consonant k changes to ż before szy, giving lżejszy.
• Finally, inflect it: for masculine singular nominative we use lżejszy. If the noun were feminine it would be lżejsza, neuter lżejsze, and so on.

Why don’t we say bardziej lekki to express ‘lighter’?

Polish allows bardziej + adjective for comparatives, but short adjectives usually have their own special forms. Native speakers say lżejszy instead of bardziej lekki. You’d use bardziej with adjectives that lack a natural comparative or sound awkward otherwise (e.g. bardziej interesujący).

What’s the difference between using niż and od in comparisons, and can I say lżejszy od too?

Both mean ‘than’ in comparisons:
• niż is a conjunction and keeps the following noun in the same case (usually nominative).
• od is a preposition that triggers the genitive case.
Both are correct:

Mój paszport jest lżejszy niż mój bagaż.
Mój paszport jest lżejszy od mojego bagażu.

What case does the noun after niż take? Why is it nominative (mój bagaż) and not genitive?

Since niż is a conjunction (not a preposition), it doesn’t change the case of the noun. The noun stays in the case it’d have on its own – here, nominative. With od you must use genitive (mojego bagażu).

Why do we need the verb jest in this sentence? In English we can say ‘My passport lighter than my luggage.’

In Polish, you almost always include a form of być (to be) in present-tense descriptive sentences. You can’t drop jest in neutral Polish; it’s required to link the subject and adjective. English sometimes omits “is” (especially in headlines), but Polish does not.

Why is mój repeated before both paszport and bagaż? Can we drop the second mój?

You can drop the second mój if the meaning stays clear:
• Mój paszport jest lżejszy niż bagaż.
Repeating mój clarifies that both items are yours and can sound more formal or emphatic, but it’s not mandatory.

How do you pronounce ż and sz in lżejszy and bagaż? They look similar.

• sz = [ʂ], like the English “sh” in show, but with the tongue slightly farther back.
• ż = [ʐ], like the “s” in measure or the “g” in garage.
Thus lżejszy sounds roughly [ˈʐɛjʂɨ], and bagaż is [baˈgaʐ].

Why is bagaż spelled with ż and not rz?

Both ż and rz represent the same sound [ʐ], but their usage is determined by etymology and spelling rules. Each word must be learned individually; bagaż comes from a root that uses ż, so it’s spelled that way.

Why is mój spelled with ó instead of o?

In Polish, ó always represents the sound [u], while o is [ɔ]. Since mój is pronounced [muj], it’s written with ó. Historically ó and o were distinct vowels, but today ó marks the [u] sound in specific words.