Când bateria este plină, laptopul merge mult mai bine.

Because Romanian usually uses the definite article attached to the end of the noun.

• baterie = a battery
• bateria = the battery
• laptop = a laptop
• laptopul = the laptop

So Romanian says bateria and laptopul where English uses separate words like the battery and the laptop.

In this sentence, both are definite because we are talking about a specific battery and a specific laptop.

Because adjectives in Romanian must agree with the noun they describe in gender and number.

Here, bateria is:

• feminine
• singular

So the adjective must also be feminine singular:

• masculine singular: plin
• feminine singular: plină

That is why we get bateria este plină.

Yes, you can also say e.

• este = the full form of is
• e = the shorter, very common spoken form

So both are correct:

• Când bateria este plină...
• Când bateria e plină...

The version with este sounds a little more full or careful; e is more natural in everyday speech.

Când means when and introduces a time clause.

So Când bateria este plină is a subordinate clause meaning when the battery is full.

It sets the condition or time frame for the main clause:

• Când bateria este plină = when the battery is full
• laptopul merge mult mai bine = the laptop works/runs much better

Because the sentence begins with a subordinate clause:

• Când bateria este plină, = subordinate clause
• laptopul merge mult mai bine. = main clause

In Romanian, when this kind of clause comes first, it is normally separated by a comma.

If you reverse the order, you usually do not need the comma:

• Laptopul merge mult mai bine când bateria este plină.

Literally, merge comes from the verb a merge, which often means to go or to walk. But in this sentence it has a very common extended meaning: to work / to run / to function.

So with machines and devices, merge often means:

• it works
• it runs
• it functions

Examples:

• Laptopul merge bine. = The laptop works/runs well.
• Nu merge. = It doesn’t work.

So here laptopul merge mult mai bine means something like the laptop works much better or runs much better.

This is the Romanian way to say much better.

Breakdown:

• bine = well
• mai bine = better
• mult mai bine = much better

So:

• bine = well
• mai bine = better
• mult mai bine = much better

Here mult strengthens the comparative, just like much in English.

Because bine is an adverb, and it modifies the verb merge.

You are not describing the laptop as good; you are describing how it works.

Compare:

• un laptop bun = a good laptop → adjective
• laptopul merge bine = the laptop works well → adverb

So bine is the correct choice because it describes the action/performance.

Because the sentence expresses a general fact or usual relationship.

Romanian often uses the present tense for things that are generally true or repeatedly true:

• Când bateria este plină, laptopul merge mult mai bine.

This means something like Whenever the battery is full, the laptop works much better, not just one single moment in time.

So the present tense works naturally here.

Yes. Romanian word order is fairly flexible, and this sentence can be reordered without changing the basic meaning.

For example:

• Când bateria este plină, laptopul merge mult mai bine.
• Laptopul merge mult mai bine când bateria este plină.

Both are correct.

The first version emphasizes the condition/time frame first. The second starts with the main point.

Yes.

In the clause bateria este plină:

• bateria = subject
• este = verb
• plină = predicate adjective / subject complement

So the structure is basically: the battery + is + full

In the second clause:

• laptopul = subject
• merge = verb
• mult mai bine = adverbial expression

Yes, and it would still be correct, but the tone changes a bit.

• merge is very common and natural in everyday Romanian for devices
• funcționează is more explicit and slightly more formal/technical

So:

• Laptopul merge mult mai bine. = very natural everyday Romanian
• Laptopul funcționează mult mai bine. = also correct, a bit more formal

Here are the main ones:

• când = when
• baterie = battery
• a fi = to be → este
• plin / plină = full
• laptop = laptop
• a merge = to go / to work / to function → merge
• mult = much
• mai = more
• bine = well

This is useful because Romanian words often appear in inflected forms, so learners need to know the base form too.