kanyousyokubutu ga kareta.

It is read:

かんようしょくぶつ が かれた。
Romanization: kanyō shokubutsu ga kareta.

• 観葉植物 = かんようしょくぶつ
• 枯れた = かれた

In normal Japanese writing, it would usually be written without spaces: 観葉植物が枯れた。

が marks 観葉植物 as the grammatical subject: the thing that withered/died.

In a simple, neutral statement describing what happened, が is very natural:

• 観葉植物が枯れた。 = The houseplant withered / died.

If you used は instead:

• 観葉植物は枯れた。

that would sound more like you are making 観葉植物 the topic, often with a contrastive or topic-setting nuance, like:

• As for the houseplant, it died.
• The houseplant, unfortunately, died.

So が is the most straightforward choice when simply reporting an event.

Yes, very often it does.

Japanese often uses the past form for a change of state that has happened:

• 枯れる = to wither, to dry up, to die off
• 枯れた = withered / has withered / died off

So 観葉植物が枯れた。 usually means the plant has reached that state. In English, depending on context, you might translate it as:

• The houseplant died.
• The houseplant has died.
• The houseplant withered.

Japanese past tense does not always match English simple past exactly. Here it often implies the result is now true.

The dictionary form is 枯れる（かれる）.

This is an ichidan verb.

Conjugation:

• Dictionary form: 枯れる
• Past plain form: 枯れた
• Negative: 枯れない
• Polite: 枯れます
• Polite past: 枯れました

So this sentence is using the plain past form.

Not exactly.

枯れる is used for things like:

• plants
• flowers
• grass
• leaves

It means to wither, to dry up, or to die off.

死ぬ is the general verb to die, and is more commonly used for:

• people
• animals

For a plant, Japanese often prefers 枯れる rather than 死ぬ.

So for a houseplant:

• 観葉植物が枯れた。 sounds natural.
• 観葉植物が死んだ。 is understandable, but less natural in ordinary usage.

It is intransitive.

That means the plant itself undergoes the change:

• 観葉植物が枯れた。 = The houseplant withered.

If you want to say someone caused a plant to wither, Japanese often uses a causative or a different phrasing, for example:

• 水をやらなくて、観葉植物を枯らしてしまった。
  I neglected to water it and ended up letting the houseplant die.

Here 枯らす is the transitive counterpart: to make something wither / to let something die.

Literally, it is made of:

• 観葉（かんよう） = ornamental leaves / foliage for viewing
• 植物（しょくぶつ） = plant

So 観葉植物 means a foliage plant, usually what English calls a houseplant or ornamental plant kept for its leaves.

In everyday translation, houseplant is often the most natural English choice.

Japanese does not usually use articles like English a or the.

So 観葉植物が枯れた。 could mean:

• A houseplant died.
• The houseplant died.

Which one is meant depends on context.

If you and the listener already know which plant you are talking about, English usually uses the:

• The houseplant died.

If it is new information:

• A houseplant died.

Japanese leaves that distinction unstated unless the context makes it important.

Yes, potentially.

Japanese nouns usually do not show singular/plural the way English does. So 観葉植物 can refer to:

• a houseplant
• houseplants

However, in a simple sentence like this, people will often assume one plant unless context suggests otherwise.

If you wanted to make plural meaning clearer, you might add something like:

• 観葉植物が何鉢か枯れた。 = Several houseplants died.
• 観葉植物たちが枯れた。 = possible, but たち is less common with things like plants and can sound stylistically marked

The basic order is:

Subject + が + verb

• 観葉植物 = subject
• が = subject marker
• 枯れた = verb

Japanese often puts the verb at the end, so this is a very standard sentence pattern.

A very literal gloss would be:

• houseplant + subject marker + withered

Natural English reorders that as:

• The houseplant withered.
• The houseplant died.

The polite version is:

観葉植物が枯れました。

• 枯れた = plain past
• 枯れました = polite past

The meaning is the same, but 枯れました is more appropriate in polite conversation, customer service, speaking to strangers, and so on.

Yes, very often.

If the context already makes it clear what you are talking about, Japanese may simply say:

枯れた。

That can mean:

• It died.
• It withered.

Japanese frequently omits subjects when they are understood from context.

By itself, it is fairly neutral and factual. It just states what happened.

But because a houseplant dying is often unfortunate, the sentence can naturally carry a sad feeling depending on context and tone of voice.

If you want to make the regret clearer, you could say things like:

• 観葉植物が枯れちゃった。 = The houseplant died on me. / My houseplant died.
• 観葉植物が枯れてしまった。 = The houseplant ended up dying.

Those versions more strongly suggest disappointment or regret.