Quid agam, si mater me domi manere cogit?

Because this is a deliberative question: Quid agam? = What am I to do? / What should I do?

In Latin, when someone is wondering what to do, the verb is often put in the present subjunctive. So:

• quid ago? would mean What am I doing?
• quid agam? means What am I to do? / What should I do?

So the subjunctive here does not mean the action is unreal; it shows hesitation, uncertainty, or deliberation.

Agam is:

• 1st person singular
• present subjunctive active
• from agere = to do, drive, act

So quid agam literally means what I may do, but in natural English it is usually translated as what should I do? or what am I to do?

Because si here introduces a simple condition: if mother forces me to stay at home.

Latin often uses the indicative in ordinary if clauses when the condition is presented as a real possibility or a straightforward fact.

So:

• si ... cogit = if ... is forcing / forces
• not a hypothetical contrary-to-fact condition

The subjunctive is only in agam because the main clause is a deliberative question.

Because after cogit (forces), Latin uses an accusative + infinitive construction.

So:

• me = me (accusative)
• manere = to stay

Together, me manere means me to stay.

This is the normal pattern after verbs of causing, ordering, saying, thinking, and similar verbs in Latin.

So:

• mater me domi manere cogit
• literally: mother forces me to stay at home

Latin does not usually say mater cogit ut ego maneam in a basic sentence like this; the accusative + infinitive is the standard construction after cogere.

Because me is the person being forced, and with cogere that person is put in the accusative as the subject of the infinitive.

Compare:

• mater me cogit = mother forces me
• me manere = me to stay

So me serves two roles at once:

1. it is the object of cogit
2. it is the logical subject of manere

That is very common in Latin.

Domi is a locative form, meaning at home.

A few words in Latin have a special form for place where, especially:

• domi = at home
• ruri = in the countryside
• names of towns and small islands also often use special case forms without a preposition

So domi manere means to stay at home, not to stay from home or to stay into home.

This is just an idiomatic Latin expression that learners need to remember.

Yes, in domo can exist, but domi is the usual and idiomatic way to say at home.

So:

• domi = the standard expression for at home
• in domo is possible in some contexts, especially if the physical building is being emphasized

In a sentence like this, domi is the natural choice.

Quid here means what?

It is the neuter singular form of the interrogative pronoun quis, quid.

In quid agam, it is the object of agam:

• quid = what
• agam = should I do

So the phrase means What should I do?

Latin word order is much more flexible because the endings show the grammatical relationships.

English depends heavily on word order:

• Mother forces me to stay at home

Latin can move parts around more freely:

• mater me domi manere cogit
• mater me cogit domi manere
• me mater domi manere cogit

All of these can work, though some orders are more natural than others.

In your sentence, the order is quite normal:

• Quid agam = the question first
• si mater me domi manere cogit = the condition afterward

It can mean either, depending on context.

Cogit is present indicative active, 3rd person singular, from cogere. Latin present tense often covers both:

• forces
• is forcing

So the sentence could be translated naturally as either:

• What should I do if my mother forces me to stay at home?
• What am I to do if my mother is forcing me to stay at home?

English chooses between simple present and progressive more sharply than Latin does.

Latin often leaves out possessives when they are obvious from context.

So mater by itself can mean:

• mother
• or, in context, my mother

Since the sentence already has me, it is easy to understand whose mother is meant. Latin frequently does this with family words.

If Latin wanted to be more explicit, it could say mater mea, but it does not need to.

Its basic meaning is to remain, stay, continue.

So domi manere is literally to remain at home, which in natural English is to stay at home.

Depending on context, manere can also suggest:

• staying behind
• remaining in a place
• continuing in the same condition

But here stay at home is exactly right.

The sentence has two parts:

1. Quid agam
   = What should I do?
   This is the main clause, a deliberative question.

2. si mater me domi manere cogit
   = if mother forces me to stay at home
   This is the conditional clause introduced by si.

So the whole sentence means:

• What should I do, if my mother forces me to stay at home?

Grammatically, it is:

• a main-question clause in the subjunctive
• followed by a normal if clause in the indicative