Die kleiplaat is leerhard.

Here die is the definite article, so it means the.

Afrikaans uses die for:

• the (definite article)
• sometimes that/those in other contexts

In Die kleiplaat is leerhard, it simply means the.

A useful thing to remember:

• Afrikaans does not have separate forms like English the for gender.
• die is used for singular and plural nouns as the definite article.

Examples:

• die boek = the book
• die boeke = the books

Because Afrikaans very often writes compound nouns as one word.

So:

• klei = clay
• plaat = slab / plate

Together:

• kleiplaat = clay slab

This is very common in Afrikaans and works much like German or Dutch-style compounding. English often writes similar ideas as two words, but Afrikaans usually prefers a single compound word.

Other examples:

• tafelblad = tabletop
• huisdeur = house door / front door
• waterbottel = water bottle

So kleiplaat is normal standard spelling.

Leerhard is an adjective.

It describes the condition of the clay slab. In pottery, leather-hard is a specific stage of drying, and Afrikaans expresses that as leerhard.

This is also a compound:

• leer = leather
• hard = hard

Together:

• leerhard = leather-hard

So the sentence structure is:

• Die kleiplaat = the clay slab
• is = is
• leerhard = leather-hard

That makes leerhard the predicate adjective after is.

Because it comes after the verb is.

In Afrikaans, adjectives used predicatively (after a verb like is) usually stay in their basic form:

• Die kleiplaat is leerhard.
• Die water is koud.
• Die kos is lekker.

But when an adjective comes before a noun, it often takes -e:

• die leerharde kleiplaat
• die koue water
• die lekker kos (some adjectives may stay unchanged, depending on the word)

So in your sentence, leerhard has no ending because it is not directly in front of the noun.

Yes, in this sentence it is very similar to English.

The pattern is:

• Subject: Die kleiplaat
• Verb: is
• Adjective/description: leerhard

So it matches English:

• The clay slab is leather-hard.

This is a straightforward main clause, and Afrikaans often looks very familiar to English speakers in simple sentences like this.

No. In Afrikaans, die is not pronounced like the English word die.

It is pronounced roughly like dee.

A rough guide to the whole sentence:

• Die ≈ dee
• klei ≈ similar to English clay
• plaat ≈ plaht
• is ≈ a short is/uhs
• leerhard ≈ leer-hart (with the h clearly pronounced)

So an approximate English-friendly pronunciation is:

dee klay-plaht is leer-hart

That is only approximate, but it is much closer than using English die.

Normally, Afrikaans writes it as leerhard, one word, without a hyphen.

English often uses hyphens in compounds like leather-hard, but Afrikaans more often prefers a closed compound form.

So:

• English: leather-hard
• Afrikaans: leerhard

Hyphens do exist in Afrikaans, but they are used for more specific spelling reasons, not automatically wherever English would use one.

Afrikaans does not capitalize all nouns.

Unlike German, Afrikaans only capitalizes:

• the first word of a sentence
• proper names
• certain special cases

So in your sentence:

• Die is capitalized because it starts the sentence
• kleiplaat is not capitalized
• leerhard is not capitalized

That is completely normal Afrikaans spelling.

Yes, if you mean a clay slab rather than the clay slab.

Compare:

• Die kleiplaat is leerhard. = The clay slab is leather-hard.
• ’n Kleiplaat is leerhard. = A clay slab is leather-hard.

So the difference is just definiteness:

• die = the
• ’n = a/an

Remember that ’n is written with an apostrophe and is usually unstressed in speech.

The plural of kleiplaat is normally kleiplate.

So:

• Die kleiplaat is leerhard. = The clay slab is leather-hard.
• Die kleiplate is leerhard. = The clay slabs are leather-hard.

A detail that often surprises English speakers: Afrikaans uses is with plural subjects in standard present tense sentences like this.

So you get:

• Die boek is nuut.
• Die boeke is nuut.

Not:

• Die boeke are... or a separate plural form of is

Afrikaans verbs do not change much for person or number in the present tense.

Yes. If you want to put the adjective before the noun, it usually changes form.

For example:

• die leerharde kleiplaat = the leather-hard clay slab

Compare:

• Die kleiplaat is leerhard. → adjective after the verb
• die leerharde kleiplaat → adjective before the noun

So this is a useful contrast:

• predicative: leerhard
• attributive: leerharde

That is a very common pattern in Afrikaans adjectives.