Ben acele kararlar almaktan korkuyorum.

Ben is optional.

Turkish verbs already show the subject, and korkuyorum means I am afraid / I fear, so the I is built in.

• Ben acele kararlar almaktan korkuyorum = I’m afraid of making hasty decisions
• Acele kararlar almaktan korkuyorum = same meaning

Using ben can add emphasis, like I am the one who feels this way.

Almaktan comes from almak (to take / to make, depending on context).

Here is the breakdown:

• al- = take
• -mak = the infinitive ending, like to take
• -tan = from

So almaktan literally means something like from taking.

With korkmak, Turkish often uses this structure to express being afraid of doing something:

• Yüzmekten korkuyorum = I’m afraid of swimming
• Hata yapmaktan korkuyor = He/she is afraid of making mistakes
• Acele kararlar almaktan korkuyorum = I’m afraid of making hasty decisions

Even though from sounds strange in English, this is normal in Turkish grammar.

Because korkmak commonly takes the ablative case in Turkish.

So Turkish says the equivalent of:

• bir şeyden korkmak = to be afraid of something
• bir şey yapmaktan korkmak = to be afraid of doing something

Examples:

• Köpekten korkuyorum = I’m afraid of dogs / of the dog
• Uçmaktan korkuyor = He/she is afraid of flying
• Yanlış yapmaktan korkuyoruz = We’re afraid of making mistakes

This is just a verb pattern you need to learn with korkmak.

Korkuyorum is the present continuous form, but in Turkish this form is also very often used for general, current states and feelings.

So:

• Korkuyorum = I’m afraid / I fear

It does not have to mean only right at this moment. It can also describe a general tendency or ongoing feeling.

Korkarım exists, but it is less neutral here and can sound more literary, formal, or like a general statement. In everyday Turkish, korkuyorum is the natural choice.

Here acele describes kararlar, so it works like an adjective: hasty / rushed.

• acele kararlar = hasty decisions

This may feel unusual to an English speaker because acele is also often seen in expressions related to haste or in a hurry.

Compare:

• acele kararlar almak = to make hasty decisions
• aceleyle karar almak = to make a decision hurriedly / in haste

These are close in meaning, but not identical:

• acele kararlar focuses on the type of decisions
• aceleyle karar almak focuses on how the action is done

Because kararlar here is an indefinite plural object.

• kararlar = decisions, some decisions, decisions in general
• kararları = the decisions, specific decisions

So:

• acele kararlar almak = to make hasty decisions
• acele kararları almak = to make/take the hasty decisions

In your sentence, the meaning is general, not about a specific set of decisions, so kararlar is the natural choice.

Yes, almak literally means to take, but karar almak is the normal Turkish expression for to make a decision.

So:

• karar almak = to make a decision
• kararlar almak = to make decisions

This is just a standard collocation. English says make a decision, while Turkish says take a decision.

Yes, singular is possible, but the meaning changes slightly.

• acele karar almaktan korkuyorum = I’m afraid of making a hasty decision
• acele kararlar almaktan korkuyorum = I’m afraid of making hasty decisions

The plural version sounds more general: it refers to a habit, tendency, or category of actions.

The singular version can sound more like one instance or the act in a more abstract, less repeated sense.

Because of consonant harmony.

The ablative ending is basically:

• -dan / -den
• but after a voiceless consonant, it becomes -tan / -ten

Since almak ends in k, which is voiceless, the ending becomes -tan:

• almak
  • -dan → almaktan

The same kind of change happens elsewhere in Turkish:

• kitap
  • -da → kitapta
• renk
  • -den → renkten

Yes. Turkish word order is flexible, although some versions sound more neutral than others.

The original sentence:

• Ben acele kararlar almaktan korkuyorum

is natural and clear.

You could also hear:

• Acele kararlar almaktan korkuyorum
• Ben korkuyorum acele kararlar almaktan
  This is possible, but less neutral and more marked.

In Turkish, the most important or focused part often comes just before the verb. The original sentence is a normal, straightforward way to say it.

It most naturally means I’m afraid of making hasty decisions.

That is, the speaker fears the act or possibility of doing that.

In English, afraid of doing and afraid to do are sometimes close, but Turkish here is clearly using the fear of an action structure:

• ... yapmaktan korkmak = to be afraid of doing ...

So the emphasis is on the action as something feared.

You could, but the nuance changes.

• acele kararlar = hasty, rushed decisions
• çabuk kararlar = quick decisions
• hızlı kararlar = fast decisions

Acele often suggests that the speed is a problem, that the decisions are made too hastily. That fits well with korkuyorum.

By contrast, quick decisions are not always bad. So acele kararlar is the best choice if the meaning is specifically rash / hasty decisions.