Learn Hardcore Czech: Tento park je velký a hezký.

tento park – literally this park; feels a bit more specific/emphatic or written/neutral style.
ten park – often just that park / the park; very common in everyday speech.

In many situations you could say ten park je velký a hezký and it would still be correct. The choice is often about nuance and style, not strict grammar.

Why does tento come before park? Could it come after?

In Czech, demonstratives like tento, ten, tamten almost always come before the noun:

tento park – this park
ten dům – that house
tamten strom – that tree over there

Putting tento after the noun (park tento) is not standard modern Czech; it would sound archaic or poetic at best. So for normal speech and writing, keep the demonstrative before the noun.

How do I know that park is masculine, and why does that matter?

You usually learn the gender from the dictionary: park, m. (masculine).

Gender matters because adjectives and some other words must agree with the noun. For park (masculine inanimate, singular, nominative) the basic adjective forms are:

masculine: velký park, hezký park
feminine: velká zahrada (big/pretty garden)
neuter: velké město (big city)

So you say velký / hezký park, not velká / hezká park.

Why do both adjectives end with -ý (velký, hezký)?

Both adjectives:

describe the same noun (park)
are in the same case (nominative)
have the same number (singular)
and the same gender (masculine inanimate)

Because of this, they must match in form: velký a hezký.

If the noun changed, the adjective endings would change too:

Ta zahrada je velká a hezká. – The garden is big and pretty. (feminine)
To město je velké a hezké. – The city is big and pretty. (neuter)

Could I say Tento velký a hezký park instead? Does it mean the same?

Yes, you can, and it is correct.

Tento park je velký a hezký. – Saying something about the park (predicative adjectives).
Tento velký a hezký park – Using the adjectives inside the noun phrase (attributive adjectives).

The meaning is similar, but the structure is different:

Tento park je velký a hezký. – Complete sentence: This park is big and pretty.
Tento velký a hezký park – Just a noun phrase: this big and pretty park (you still need a verb to make a full sentence).

What exactly is je, and how is the verb být (to be) conjugated?

je is the 3rd person singular present form of být (to be): he/she/it is.

Present tense of být:

já jsem – I am
ty jsi – you are (singular, informal)
on/ona/ono je – he/she/it is
my jsme – we are
vy jste – you are (plural OR polite singular)
oni jsou – they are

So Tento park je velký a hezký. literally: This park is big and pretty.

How would I turn this sentence into a yes/no question in Czech?

You mostly change intonation and sometimes the word order:

Je tento park velký a hezký? – Is this park big and pretty?
Je tenhle park velký a hezký? – (more colloquial with tenhle)

Simply raising your voice at the end can already signal a question, but switching to Je tento park…? is very common and clear. You don’t need a special word like do/does in English.

Is there anything in Czech like the English articles a / the?

Czech has no articles like English a, an, the.

park alone can mean a park or the park, depending on context.
ten / tento / tamten are demonstratives, not articles, but they sometimes play a similar role to this / that / that over there.

So Park je velký a hezký. can mean The park is big and pretty or A park is big and pretty, depending on the situation.

How do I pronounce Tento park je velký a hezký?

Approximate pronunciation for an English speaker (stress is always on the first syllable in Czech):

Tento – TEN-toh
park – like English park, but r is tapped/rolled a bit
je – yeh (like yeah without the final -ah)
velký – VEL-kee (long í as in vee)
a – ah
hezký – HEZ-kee (again long ý/í sound)

Notes:

j is always like English y in yes.
ý and í indicate a long ee sound.
Stress doesn’t move around like in English; it stays on the first syllable of each word.

What’s the difference between hezký and krásný?

Both can be translated as nice / pretty / beautiful, but there is a nuance:

hezký – nice, pretty, pleasant looking; very common, quite neutral.
krásný – beautiful, gorgeous; usually stronger praise.

So:

hezký park – a nice, pleasant park.
krásný park – a beautiful, really impressive park.

In everyday speech, hezký is slightly more frequent, but krásný is also very common.

Can I swap the adjectives and say Tento park je hezký a velký?

Yes, you can. Both:

Tento park je velký a hezký.
Tento park je hezký a velký.

are grammatically correct.

The difference is very small; often you put the more basic / objective quality first (big) and the more subjective quality second (pretty), which makes velký a hezký feel slightly more natural, but both orders are acceptable.

How would I make this sentence negative?

You negate the verb je by adding ne- to form není:

Tento park není velký a hezký. – This park is not big and pretty.

If you want to say neither big nor pretty, you normally use ani:

Tento park není velký ani hezký. – This park is neither big nor pretty.

So:

ne attaches to the verb: je → není
ani joins the two adjectives in a negative list.

How does the sentence change in the plural (for several parks)?

For more than one park, use plural forms:

Tyto parky jsou velké a hezké. – These parks are big and pretty.

Changes:

tento park → tyto parky (these parks)
je (is) → jsou (are)
velký / hezký → velké / hezké (plural adjective endings for masculine inanimate nouns)

So adjectives and the verb both agree with the new plural noun.

Why is the conjunction a used? What’s the difference between a, i, and ani?

In this sentence you have:

a – the basic and: velký a hezký – big and pretty.

Other related words:

i – also and, but often with a sense of also / even / both
- Je velký i hezký. – He is both big and pretty / He is big and also pretty.
ani – and not / nor in negative contexts
- Není velký ani hezký. – He/It is neither big nor pretty.

So a is the neutral coordinator here; i and ani add an extra nuance (both / neither).

What case are the words in, and when would they change?

In Tento park je velký a hezký. everything is in the nominative case, because:

tento park – the subject
velký, hezký – predicative adjectives describing the subject

Nominative is used mainly for the subject of the sentence.

If you change the role, the case changes, and the forms change too:

Vidím tento velký a hezký park. – I see this big and pretty park.
- tento… park is now in the accusative (direct object), though it looks the same here in singular masculine inanimate.

In other sentences and with other genders, you’ll see clearer changes, but the key idea is: case depends on the word’s role in the sentence, and adjectives/demonstratives follow the noun.