Modul acesta este simplu.

Because -ul is the Romanian definite article attached to the end of the noun.

• mod = way, method, manner
• modul = the way, the method

Romanian usually puts the at the end of the noun instead of using a separate word like English does.

So:

• mod = a way / a method
• modul = the way / the method

In modul acesta, the noun is definite, so modul is the correct form.

In Romanian, a demonstrative like this can often come after the noun.

So:

• modul acesta = this way / this method

This structure is very common in Romanian. English puts this before the noun, but Romanian can place it after.

A similar idea exists with:

• băiatul acesta = this boy
• cartea aceasta = this book

So even though the word order looks unusual to an English speaker, it is perfectly normal in Romanian.

Yes, they are very close in meaning. Both mean this way / this method.

The difference is mostly one of structure and style:

• acest mod = demonstrative before the noun
• modul acesta = noun with definite article + demonstrative after it

Both are correct Romanian. In many everyday contexts, modul acesta sounds very natural.

One important detail: if the demonstrative comes before the noun, you use acest mod, not acesta mod.

So:

• acest mod ✅
• modul acesta ✅
• acesta mod ❌

Here mod means something like:

• way
• method
• manner

So the sentence could refer to a way of doing something, a procedure, or a method.

A learner should be careful not to assume it means English mode in every context. In this sentence, the natural sense is way / method.

Because mod is a neuter noun in Romanian, and neuter nouns behave like:

• masculine in the singular
• feminine in the plural

Since this sentence is singular, the adjective takes the masculine singular form:

• simplu = masculine/neuter singular
• simplă = feminine singular

So:

• modul acesta este simplu ✅
• modul acesta este simplă ❌

Mod is a neuter noun.

That matters because Romanian adjectives and demonstratives have to agree with the noun in gender and number.

In the singular:

• neuter nouns use masculine-type forms

That is why you get:

• acesta
• simplu

If it were plural, the forms would change accordingly.

Este means is. It is the 3rd person singular form of a fi, which means to be.

So the structure is:

• Modul acesta = subject
• este = is
• simplu = simple

In normal standard Romanian, este is kept here. English speakers sometimes expect it might be dropped, but in a sentence like this, you normally say it.

So:

• Modul acesta este simplu = normal and correct

The sentence breaks down like this:

• modul acesta = this method / this way
  
  • modul = the method / the way
  • acesta = this
• este = is
• simplu = simple

So the overall pattern is:

• subject + to be + adjective

This is very similar to English:

• This method is simple

The biggest differences from English are:

• the definite article is attached to the noun
• the demonstrative can come after the noun

In the plural, mod becomes moduri, and the definite plural is modurile.

So:

• modurile acestea sunt simple = these methods are simple

Notice the agreement changes:

• acesta → acestea
• este → sunt
• simplu → simple

This shows the neuter pattern clearly: in the plural, neuter nouns behave like feminine nouns.

It is pronounced roughly like a-CHES-ta, with the stress on the middle syllable.

A rough English-friendly guide:

• a as in about
• ces with ch like in check
• ta like tah

So approximately:

• a-CHES-ta

The exact Romanian sounds are a little different from English, but that approximation is useful for beginners.