Learn Hardcore Spanish (Latin America): Este curso es muy interesante.

You may see éste (with accent) in older texts, but current standard Spanish (RAE rules) recommends este without an accent when it comes before a noun:

este curso, esta casa, estos libros, estas personas

An accent is now only possible (and even then not required) when the word stands alone and there could be ambiguity, e.g.:

Este es mejor que ese.

Even there, most modern writing still uses este without an accent. So in your sentence, este is correct and normal.

Why is curso masculine? How can I tell the gender of nouns like this?

In Spanish, every noun has a grammatical gender, usually masculine or feminine. A common pattern:

Nouns ending in -o are usually masculine: curso, libro, perro
Nouns ending in -a are usually feminine: casa, mesa, persona

There are exceptions (e.g., el día, la mano), but curso follows the regular pattern: it ends in -o, so it is masculine. That’s why you use:

el curso (the course)
este curso (this course)
adjectives in the masculine form when needed (e.g., curso largo)

What’s the difference between curso and clase?

Both can translate as “class” in English, but they refer to slightly different things:

curso
- A course or a full program of study.
- More long-term: a semester course, a yearly course, an online course.
- Example: Estoy tomando un curso de español. (I’m taking a Spanish course.)
clase
- A class session or lesson, or the group of students.
- More short-term and specific: today’s class.
- Example: Tengo clase de español a las 10. (I have Spanish class at 10.)

In Este curso es muy interesante, the speaker is talking about the whole course, not just a single class session.

Why is it es and not está? Aren’t both of them “is”?

Spanish uses two different verbs for “to be”:

ser (here: es) is used for more permanent or defining characteristics.
estar (here: está) is used for temporary states, conditions, or locations.

In Este curso es muy interesante, es (from ser) presents “being interesting” as a general, defining characteristic of the course. It’s part of how the course is.

If you say:

Este curso está muy interesante.

you’re usually emphasizing your current impression at this moment or during this part of the course, as if it has become interesting or is especially interesting right now.

Can I say Este curso está muy interesante? Does it mean the same thing?

You can say it, and it is natural, but there is a nuance:

Este curso es muy interesante.
- General, more “objective” description.
- The course, in general, is interesting by nature.
Este curso está muy interesante.
- Focuses on how it feels now or at this stage.
- Sounds more like: “This course is really interesting (these days / at this point).”

Both are correct; es sounds more like a stable quality, está like a current state or impression.

Why is muy used instead of mucho?

Muy and mucho both relate to “a lot,” but they are used differently:

muy goes before adjectives and adverbs:
- muy interesante = very interesting
- muy rápido = very fast
- muy bien = very well
mucho / mucha / muchos / muchas usually go with nouns, or appear as adverbs on their own:
- with nouns: mucho trabajo (a lot of work), mucha agua (a lot of water)
- as an adverb: trabaja mucho (he/she works a lot)

In your sentence, interesante is an adjective, so you need muy interesante, not mucho interesante.

Does interesante change for gender or number?

Interesante is one of the adjectives that ends in -e, and those usually do not change for masculine vs. feminine:

un curso interesante (masculine, singular)
una clase interesante (feminine, singular)

But it does change for number:

unos cursos interesantes (masculine, plural)
unas clases interesantes (feminine, plural)

So:

Singular: interesante
Plural: interesantes

Where can muy go in the sentence? Can I move it around?

In this kind of sentence, muy must come right before the adjective:

Correct: Este curso es muy interesante.
Incorrect: Este curso es interesante muy.
Incorrect: Este curso muy es interesante.

If you want a different emphasis, you normally change the adjective, not the position of muy, for example:

Este curso es interesantísimo. (This course is extremely interesting.)

Why is there no separate word for “it” like in English “It is very interesting”?

In English you say It is very interesting, where it is a dummy subject. In Spanish, the subject is usually expressed directly in the sentence:

Este curso = the subject (“this course”)
es = is
muy interesante = very interesting

So Este curso es muy interesante literally means “This course is very interesting.” There is no need for an extra “it,” because este curso already fills that role. Spanish doesn’t use a dummy pronoun like English does here.

How do you pronounce curso and interesante in Latin American Spanish?

Approximate pronunciation (general Latin American):

curso → [KOOR-soh]
- cu = like “koo” in “cool”
- r = single tap, similar to a very quick “d” in American English “ladder”
- so = “so” with a pure “o” (like in Italian), not like English “soʊ”
interesante → [een-teh-reh-SAN-teh]
- in = “een”
- te = “teh”
- re = “reh”
- san = “sahn” (a short, pure “a”)
- te again = “teh”
- Stress falls on -san-: in-te-re-SAN-te

In Latin American Spanish, the c in curso is always like English k (never “th” as in some Spain accents), and vowels are short and pure, not diphthongized like many English vowels.