Haec exercitatio aspera est, sed magistra dicit nos eam perficere posse.

Because exercitatio is a feminine noun, so the demonstrative must also be feminine.

• hic = this (masculine)
• haec = this (feminine)
• hoc = this (neuter)

Here, haec agrees with exercitatio in gender, number, and case, so haec exercitatio means this exercise.

A learner may expect something like hoc because English this does not change form, but Latin demonstratives do.

Exercitatio is nominative singular.

It is the subject of est, so it has to be in the nominative:

• Haec exercitatio aspera est = This exercise is difficult/harsh

Also, exercitatio is the dictionary form of the noun, which is another clue that it is nominative singular.

Because it agrees with exercitatio.

Even though aspera comes after exercitatio and after est, it is still describing the subject, so it must match:

• exercitatio = feminine singular nominative
• aspera = feminine singular nominative

This is called a predicate adjective: an adjective linked to the subject by est.

Not literally in the narrowest sense. Asper basically means rough, harsh, or hard. In context, it can naturally mean difficult or challenging.

So in this sentence, aspera est is a very natural way to express the idea that the exercise is hard.

Because magistra is the subject of dicit.

The sentence has two main parts:

• Haec exercitatio aspera est
• sed magistra dicit nos eam perficere posse

In the second part, magistra is the one doing the saying, so it is nominative.

Because after a verb like dicit, Latin often uses an indirect statement, and in that construction the subject of the reported statement goes into the accusative.

So:

• nos ... posse = that we can ...

Here, nos is not the subject of dicit. It is the subject of the reported idea inside the indirect statement.

If this were direct speech, it would be:

• Nos eam perficere possumus = We can complete it

But after dicit, Latin changes that to:

• dicit nos eam perficere posse

Eam means her/it in the accusative feminine singular, and here it refers back to exercitatio.

Since exercitatio is feminine singular, the pronoun referring to it must also be feminine singular:

• exercitatio → eam

And because it is the direct object of perficere, it must be in the accusative.

So:

• eam perficere = to complete it

For two different reasons:

1. Posse is infinitive because it is part of an indirect statement after dicit.
2. Perficere is infinitive because posse normally takes another infinitive:
   • posse facere = to be able to do
   • posse perficere = to be able to complete

So nos eam perficere posse means that we are able to complete it.

Because Latin usually does not use a separate word like English that in this kind of sentence.

Instead, it uses the accusative-and-infinitive construction:

• magistra dicit
• nos eam perficere posse

Literally, this is something like:

• the teacher says us to be able to complete it

But good English turns that into:

• the teacher says that we can complete it

So the idea of that is built into the Latin construction, not expressed by a separate word.

Because possumus would be used in direct speech, while posse is used in indirect statement.

Compare:

• Direct: Nos eam perficere possumus.
• Indirect after dicit: Magistra dicit nos eam perficere posse.

This is one of the most important patterns in Latin:

• direct statement uses a normal finite verb
• indirect statement often changes that verb to an infinitive

Latin word order is more flexible than English word order.

Putting posse at the end is very natural in Latin, especially in an indirect statement. The whole phrase nos eam perficere posse acts as the thing that magistra dicit.

So the sentence builds toward its final idea:

• the teacher says
• that we
• it
• complete
• can

English usually fixes the order more strictly, but Latin often saves an important verb for the end.