màikèfēng xiànzài zhèngcháng le.

Here, 了 marks a change of state.

So 麦克风现在正常了 suggests that the microphone was not normal / was not working properly before, but now it is.

A very literal way to feel it is:

• The microphone is normal now.
• with the extra idea: it has become normal now

This sentence-final 了 often appears when something has changed, especially into a new situation.

Compare:

• 麦克风现在正常。 = The microphone is normal now.
  
  • This sounds more like a plain statement of its current condition.
• 麦克风现在正常了。 = The microphone is normal now.
  
  • This strongly suggests it wasn’t okay before, but now it is.

Because 正常 is an adjective / stative predicate, and in Mandarin, adjectives can often act as the main predicate without 是.

So:

• 他很高。 = He is tall.
• 天气很热。 = The weather is hot.
• 麦克风现在正常了。 = The microphone is normal / working properly now.

English usually needs to be (is, are, was), but Mandarin often does not.

In fact, 麦克风现在是正常了 would usually sound unnatural in this context.

In this sentence, 正常 most naturally means working properly / functioning normally.

With machines, devices, systems, or body functions, 正常 often has the sense of:

• functioning as expected
• back to normal
• okay again

So for a microphone, 正常了 usually means:

• it’s working now
• it’s back to normal
• the problem is fixed

The exact English translation depends on context, but working properly is often the most natural choice.

现在 is a time word, and in Mandarin, time words usually come before the predicate.

The structure here is:

• 麦克风 = topic/subject
• 现在 = now
• 正常 = normal / functioning properly
• 了 = change of state

So the sentence is:

• 麦克风 现在 正常 了。

This placement is very normal in Mandarin.

You can think of the pattern as:

Topic/Subject + Time + Predicate

Examples:

• 我今天很忙。 = I’m busy today.
• 他现在在家。 = He’s at home now.
• 机器已经好了。 = The machine is already fixed.

It can be understood as both, but it’s especially helpful to think of it as the topic.

Mandarin often uses a topic-comment structure:

• 麦克风 = as for the microphone
• 现在正常了 = it’s normal now / it’s working now

So a very literal breakdown is:

• As for the microphone, it’s normal now.

This is one reason Mandarin can feel different from English. English is more strictly subject-based, while Mandarin often organizes sentences by what we’re talking about first, then what we say about it.

Because Mandarin often does not need a separate verb where English does.

In English, we often say:

• The microphone is working now.

In Mandarin, using 正常 alone can express that idea naturally, especially for devices or systems.

So instead of saying something equivalent to the microphone works normally now, Mandarin can simply say:

• 麦克风现在正常了。

Other natural ways to express a similar idea would be:

• 麦克风现在能用了。 = The microphone can be used now.
• 麦克风恢复正常了。 = The microphone has returned to normal.

But your original sentence is already very natural.

Yes, but the meaning or nuance changes.

1. Without 现在

• 麦克风正常了。

This still means the microphone is normal / working again, and 了 still shows a change of state.
It may sound a little more like The microphone is fixed now / It’s okay now, with now understood from context.

2. Without 了

• 麦克风现在正常。

This is more like a neutral description of the current state:
The microphone is normal now or The microphone is functioning normally now.

It does not emphasize the change as strongly.

3. Without both

• 麦克风正常。

This sounds like a plain statement:
The microphone is normal / functioning properly.

So:

• 了 = highlights change
• 现在 = explicitly says now

No. 麦克风 is a transliteration of the English word microphone.

The syllables are chosen mainly for sound:

• 麦 mài
• 克 kè
• 风 fēng

It does not literally mean anything like wheat-gram-wind in this context. The characters are being used for their pronunciation.

There is also a more native Chinese word:

• 话筒 = microphone / handset / mic

In everyday speech, 麦克风 is very common and natural.

Yes, very often.

Because of the sentence-final 了, many listeners will assume there was a previous problem, for example:

• it wasn’t working before
• it was broken
• the sound was abnormal
• it has just been fixed or adjusted

So if someone says:

• 麦克风现在正常了。

it often implies something like:

• The microphone is okay now.
• The microphone is working again now.

That “before vs. now” contrast is exactly the kind of thing 了 often signals.

A very natural question would be:

• 麦克风现在正常了吗？

This means:

• Is the microphone working properly now?
• Is the microphone okay now?

The pattern is simply:

statement + 吗

So:

• 麦克风现在正常了。 = The microphone is normal now.
• 麦克风现在正常了吗？ = Is the microphone normal now?

You could also ask more conversationally:

• 麦克风现在正常不正常？ = Is the microphone normal now or not?
• 麦克风现在好了吗？ = Is the microphone okay now?