Mater timet ne filius in bibliotheca studium neglegat et tantum imagines spectet.

After verbs of fearing, Latin uses a special construction:

• timeo / metuo / vereor + ne = fear that something will happen
• timeo / metuo / vereor + ut = fear that ... not / fear that something will not happen

So in this sentence, ne does not make the clause negative in the English sense. It introduces the thing the mother is afraid of.

So:

• Mater timet ne filius ... neglegat = The mother fears that her son may neglect ...

An older English equivalent is lest.

Because they are inside a fear clause, and fear clauses take the subjunctive.

Here:

• neglegat = present subjunctive of neglegere
• spectet = present subjunctive of spectare

Latin is not saying these actions are unreal; it is simply using the normal grammar for a clause after timet.

This is because of sequence of tenses.

The main verb is:

• timet = present tense

After a present main verb, Latin normally uses a present subjunctive for an action that is happening at the same time or is still in the future from that point of view.

So:

• timet ... neglegat ... spectet = she fears that he may neglect ... and may look at ...

If the main verb were past, you would usually expect the imperfect subjunctive instead:

• Mater timebat ne filius ... neglegeret et ... spectaret.

In this kind of clause, the subject stays in the nominative.

That is because ne filius ... neglegat is a finite subordinate clause with its own verb in the subjunctive. In a finite clause, the subject is nominative.

Latin uses an accusative subject mainly in an indirect statement with an infinitive, not here.

So:

• filius is the subject of neglegat and spectet
• therefore it is nominative singular

bibliotheca is ablative singular because in with the ablative means in / at a place.

Latin distinguishes:

• in + ablative = location, in / at
• in + accusative = motion into, into

So:

• in bibliotheca = in the library
• but in bibliothecam would mean into the library

Here the son is located in the library, not moving into it.

They are both direct objects:

• studium is the object of neglegat
• imagines is the object of spectet

More specifically:

• studium = accusative singular
• imagines = accusative plural

So the structure is:

• filius ... studium neglegat
• filius ... imagines spectet

Latin often uses studium in the singular as an abstract noun meaning things like:

• study
• application
• scholarly effort
• schoolwork

English often prefers the plural studies in this context, but Latin does not have to match English number exactly.

So a singular studium can naturally be translated as study or studies, depending on the context.

Here tantum is being used adverbially and means only or merely.

So:

• tantum imagines spectet = may only look at pictures / may merely look at pictures

It limits the action: instead of doing proper study, he just looks at pictures.

In other contexts, tantum can also mean so much, but here only is the natural sense.

It is still part of the same fear clause.

The whole clause introduced by ne contains two coordinated subjunctive verbs:

• neglegat
• spectet

So the structure is basically:

• Mater timet ne filius ... neglegat et ... spectet.

You do not need to repeat ne before the second verb, because the first ne already governs both.

Latin often leaves out possessive words when they are obvious from the context.

Here it is clear that the study being neglected is the son’s own, so Latin can simply say:

• studium neglegat

If Latin wanted to say his own study explicitly, it could use suum:

• studium suum neglegat

But that is not necessary.

Because Latin has no articles.

There is no separate word for:

• the
• a / an

So words like mater, filius, and bibliotheca can be translated in different ways depending on context:

• mother / the mother / a mother
• son / the son / her son
• library / the library / a library

English has to choose an article; Latin does not.

Because after verbs of fearing, Latin normally uses a subordinate subjunctive clause with ne or ut, not a simple infinitive.

So Latin says:

• timet ne ... neglegat

rather than something like timet neglegere, which would not express the same idea.

This is just the standard Latin pattern for fear:

• fear + ne/ut + subjunctive

Latin word order is much more flexible than English word order, because the endings show the grammar.

This sentence puts:

• Mater timet first, to state the main idea
• then the feared situation
• and tantum right before imagines spectet, which helps emphasize only

A Latin author could rearrange many of these words without changing the basic meaning, though the emphasis might change.

So the order here is natural, but not the only possible order.