На работе я принимаю важные решения спокойно.

Because на работе is the normal Russian expression for at work.

Even though English uses at, Russian often uses на with places connected to activities or institutions. So:

• на работе = at work
• на уроке = in class / at the lesson
• на заводе = at the factory

В работе usually means something different, more like in the work/process or in operation/use, not simply at work as a location or situation.

Работе is in the prepositional case.

The phrase на работе uses на + prepositional when talking about being at a place. The dictionary form is работа, and in the prepositional singular it becomes:

• работа
• на работе

So the -е ending shows that case.

Yes, Russian can often leave it out.

The verb принимаю already shows I because the -ю ending marks 1st person singular. So both of these are possible:

• Я принимаю важные решения спокойно.
• Принимаю важные решения спокойно.

Including я can add clarity, contrast, or emphasis. In a neutral sentence, it is often optional.

By itself, принимать can mean things like take, accept, receive, depending on context. But in this sentence it is part of the fixed expression:

принимать решение / принимать решения

This means to make a decision / make decisions.

So Russian says literally something like to take/accept a decision, but the natural English translation is make a decision.

That is just the normal collocation in Russian.

Languages do not always match word-for-word in these set expressions. English says:

• make a decision

Russian says:

• принимать решение

This is something worth learning as a chunk, not as a literal translation rule.

This is the accusative plural, because решения is the direct object of принимаю.

You are making / taking what?
важные решения

Now the important part: for inanimate plural nouns in Russian, the accusative plural looks the same as the nominative plural. So:

• nominative plural: важные решения
• accusative plural: важные решения

That is why the form looks unchanged.

Because спокойно is an adverb.

It describes how the action is done:

• принимаю решения как? — спокойно
• How do I make decisions? — calmly

If you used спокойный / спокойная, that would be an adjective describing a noun, not the manner of the action.

So:

• спокойный человек = a calm person
• говорить спокойно = to speak calmly
• принимать решения спокойно = to make decisions calmly

Yes, Russian word order is flexible.

Putting спокойно at the end is very natural because it gives the sentence a smooth rhythm and places the manner word in a noticeable final position.

But other orders are also possible, for example:

• На работе я спокойно принимаю важные решения.
• Я на работе принимаю важные решения спокойно.

These all mean roughly the same thing, but the focus changes slightly. Russian word order often reflects emphasis more than strict grammar.

Yes, принимаю is present tense imperfective.

In Russian, the present tense of an imperfective verb can describe:

• what someone is doing now
• what someone does regularly
• a general habit

So here it most naturally means a habitual or characteristic action: this is how the speaker behaves at work.

Принимаю is imperfective.

The imperfective aspect is used because the sentence describes a repeated or general action, not one completed single event. It suggests:

• a regular pattern
• a typical way of behaving
• an ongoing ability or habit

If you wanted a single completed future decision, you would more likely use a perfective form, for example приму in the right context.

Sometimes, but not always.

Решать means to decide or to solve, depending on context.
Принимать решение specifically means to make a decision.

So:

• Я принимаю важные решения спокойно. = I make important decisions calmly.
• Я спокойно решаю, что делать. = I calmly decide what to do.

The sentence with принимать решения sounds especially natural when talking about the act of decision-making itself.

It can suggest both, depending on context.

На работе can mean:

• physically at work
• more broadly in the workplace / in my job

In this sentence, it naturally refers to the work setting in general, not just standing inside a particular building. So it can be understood as at work / in my work life.

Yes, the main stresses are:

• на рабо́те
• я принима́ю
• ва́жные реше́ния
• споко́йно

This can help with pronunciation and rhythm. A natural reading would sound something like:

На рабо́те я принима́ю ва́жные реше́ния споко́йно.

Russian stress is important because it is not always predictable, so it is useful to learn stressed forms early.