Magistra discipulam constantem laudat, quia numquam cessat; discipulum pigrum reprehendit, quia opus semper differt.

Latin normally has no articles. So magistra can mean teacher, the teacher, or a teacher, depending on context. The same is true for discipulam, discipulum, and opus.

English must usually choose the or a, but Latin does not.

Yes. They are the feminine and masculine forms of student:

• discipula = female student
• discipulus = male student

In this sentence:

• discipulam constantem = the steadfast female student
• discipulum pigrum = the lazy male student

So the teacher is praising a girl student and criticizing a boy student.

Because they are direct objects, so they must be in the accusative case.

The teacher is doing the action to them:

• magistra ... laudat = the teacher praises the female student
• magistra ... reprehendit = the teacher criticizes the male student

So:

• discipula → discipulam in the accusative singular
• discipulus → discipulum in the accusative singular

This is one of the most basic uses of the accusative in Latin.

Because the two adjectives belong to different declension patterns, even though both must agree with the noun they describe.

constantem

This comes from constans, constantis, a third-declension adjective.
Its accusative singular masculine/feminine form is constantem.

So:

• discipulam constantem = steadfast female student
  Both words are accusative singular feminine.

pigrum

This comes from piger, pigra, pigrum, a first/second-declension adjective.
Its accusative singular masculine form is pigrum.

So:

• discipulum pigrum = lazy male student
  Both words are accusative singular masculine.

The important rule is: adjectives agree with the nouns they describe in gender, number, and case, but not necessarily in the exact kind of ending, because different adjectives decline differently.

Because magistra is the subject of both main verbs:

• laudat = praises
• reprehendit = criticizes

The subject goes in the nominative case, and magistra is nominative singular.

So the basic structure is:

• Magistra ... laudat = The teacher praises ...
• Magistra ... reprehendit = The teacher criticizes ...

The subject is stated once and understood with both verbs.

Latin often leaves subject pronouns unstated when the verb ending already shows the person and number.

Both cessat and differt are third person singular, so they mean:

• cessat = he/she/it stops
• differt = he/she/it postpones

The actual subject is understood from context:

• quia numquam cessat = because the steadfast female student never stops
• quia opus semper differt = because the lazy male student always postpones the work

So Latin does not need to add separate words for she or he here.

Because opus is a neuter noun, and neuter nouns often have the same form in the nominative and accusative.

So here opus is accusative singular, even though it looks the same as the nominative.

Its dictionary form is:

• opus, operis = work, task

In the sentence:

• opus semper differt = he always postpones the work / task

So opus really is the object, even though its form does not change the way a masculine or feminine noun usually does.

Quia introduces a reason clause: because.

So:

• laudat, quia numquam cessat = she praises her because she never stops
• reprehendit, quia opus semper differt = she criticizes him because he always postpones the work

After quia, Latin normally uses the indicative when the reason is presented as a real fact. That is what we have here:

• cessat = indicative
• differt = indicative

The teacher’s reasons are being stated directly.

All four verbs are third person singular, and in this sentence they are understood as present tense:

• laudat = she praises
• cessat = she stops / she is stopping
• reprehendit = she criticizes
• differt = he postpones

This gives the sentence a general, present-time sense: it describes what the teacher does and why.

A learner should especially notice the -t ending, which is the normal sign of third person singular in the present tense.

Latin word order is more flexible than English word order because case endings show who is doing what.

This sentence is arranged in a very natural way:

• Magistra discipulam constantem laudat
• discipulum pigrum reprehendit

A Latin writer often places the verb near the end, which is what happens with laudat, reprehendit, and also in the quia clauses with cessat and differt.

The order also helps the sentence feel balanced:

• praise + reason
• criticism + reason

So the order is not the only possible one, but it is a clear and elegant one.

The semicolon separates two closely connected main clauses:

• Magistra discipulam constantem laudat, quia numquam cessat
• discipulum pigrum reprehendit, quia opus semper differt

The two halves are parallel in structure, so the semicolon helps the reader see that balance clearly.

Latin could also use et, or the ideas could be split into two separate sentences, but the semicolon is a neat way to join two related thoughts without making them feel like one single clause.

Not exactly. In Latin, constans often means something more like:

• steadfast
• reliable
• persistent
• firm

So discipulam constantem suggests a student who keeps going and does not give up. That fits very well with quia numquam cessat = because she never stops.

So although English constant is related, the Latin word here is best understood as steadfast or persistent, not just unchanging.