Learn Hardcore Indonesian: Tolong bicara lebih keras agar nenek bisa mengerti. - Please speak louder so that Grandma can understand.

As a verb, menolong means to help.
As a bare form at the beginning of a sentence (Tolong + verb…), it softens a command and turns it into a polite request.

So Tolong bicara lebih keras… ≈ Please speak louder…, not Help speak louder… in English.

Why is there no you in the sentence? Why not Kamu tolong bicara lebih keras?

Indonesian often drops pronouns when the subject is clear from context, especially in commands/requests.

Bicara lebih keras is an imperative: Speak louder.
Adding tolong makes it a polite request: (Please) speak louder.
The you is understood from context (you’re talking to someone directly).

You can say:

Kamu tolong bicara lebih keras…
Tolong kamu bicara lebih keras…

but in everyday speech they usually just say Tolong bicara lebih keras….

What is the difference between bicara and berbicara? Could I say Tolong berbicara lebih keras?

Both bicara and berbicara mean to speak, and both are correct here.

Nuance:

bicara – slightly more casual, very common in spoken Indonesian.
berbicara – a bit more formal or bookish, often seen in writing or formal speech.

So:

Tolong bicara lebih keras… – natural, everyday.
Tolong berbicara lebih keras… – also correct, feels a little more formal.

In conversation with family (like nenek, grandmother), bicara sounds more natural.

Why does lebih keras (literally more hard) mean louder?

Indonesian uses keras for both hard/firm and loud (in terms of sound).

keras = hard (texture/force) or loud (sound).
lebih = more.

So lebih keras = more loud → louder.

Some related words:

suara keras – a loud voice.
musik keras – loud music.
berbicara keras-keras – speak loudly.

So bicara lebih keras is the natural way to say speak louder.

Could we say lebih kencang or lebih tinggi instead of lebih keras?

Sometimes, but the meaning shifts:

lebih keras – louder (volume). This is the most neutral/common for speak louder.
lebih kencang – can also mean louder, but often used for:
- speaking faster or in a more intense/strong way,
- or for speed (e.g. lari lebih kencang = run faster).
lebih tinggi – normally refers to higher pitch or higher volume on a scale, but used less naturally than lebih keras for everyday louder.

For this sentence, lebih keras is the best, most idiomatic choice.

What does agar do here? How is agar different from supaya or untuk?

agar introduces a purpose or goal, similar to so that or in order that.

Tolong bicara lebih keras agar nenek bisa mengerti. → Please speak louder so that Grandma can understand.

Comparison:

agar – slightly formal; common in both speech and writing.
supaya – very common in speech; same meaning as agar; a bit more informal.
untuk – usually for / to (do something), not as strong for so that.

You can also say:

Tolong bicara lebih keras supaya nenek bisa mengerti.

That sounds completely natural in conversation and slightly more colloquial than agar.

Does nenek mean grandmother in general, or my grandmother here?

It can mean either, depending on context.

Indonesian kinship terms (ibu, ayah, kakak, nenek, etc.) often double as:

General nouns (nenek = an old lady / a grandmother).
Family terms used as you or my X when speaking directly to that person.

In this sentence, context usually implies:

If you are talking to your own grandmother: nenek ≈ Grandma / Granny / Nan (as a form of address, you).
If you are talking about someone’s grandmother: nenek ≈ (the) grandmother / (someone’s) grandma.

If you need to be explicit:

nenek saya – my grandmother.
nenek kamu / nenekmu – your grandmother.

Why don’t we say nenek saya here if we mean my grandmother?

You can say nenek saya, but when you are directly involving or addressing her, just nenek is usually enough and sounds more natural.

Compare:

Tolong bicara lebih keras agar nenek bisa mengerti. – could be said to someone else about your grandma who is present.
Tolong bicara lebih keras agar nenek saya bisa mengerti. – emphasizes my grandmother, for clarity (e.g. if there are several older women present).

In many families, people will simply use Nenek as a title/name, without saya.

What is the function of bisa here? Could we leave it out and just say agar nenek mengerti?

bisa means can / be able to.

nenek bisa mengerti – Grandma can understand (has the ability to understand in this situation).

If you say:

agar nenek mengerti – so that Grandma understands.

This is still correct, just slightly different nuance:

With bisa: focuses on enabling her ability to understand (because you speak louder).
Without bisa: more on the result/state of her understanding.

In everyday speech, both are fine. Using bisa is very common and sounds natural here.

Is mengerti different from paham? Which is more natural here?

Both mean to understand.

mengerti – neutral, common in both spoken and written Indonesian.
paham – also common; sometimes feels a bit more informal/colloquial, but is widely used.

You could say:

Tolong bicara lebih keras agar nenek bisa mengerti.
Tolong bicara lebih keras agar nenek bisa paham.

Both sound natural. mengerti is slightly more neutral/formal; paham is very common in everyday speech and also in some formal contexts.

Is the whole sentence polite? Would this be okay to say to a stranger or only to family?

Yes, it is polite. The politeness comes mainly from:

tolong at the beginning (softens the command).
Indirectness: you’re saying you want Grandma to understand, not criticizing the listener.

To talk to or about an older stranger, you might adjust the kinship term:

Tolong bicara lebih keras agar Ibu bisa mengerti.
(to a woman, Ibu = ma’am/mrs/mother)
Tolong bicara lebih keras agar Bapak bisa mengerti.
(to a man, Bapak = sir/mr/father)

For your own grandmother, nenek is fine and affectionate.

Can I change the word order, like putting agar nenek bisa mengerti at the beginning?

You can move the purpose clause, but you need to keep it clear and natural.

Acceptable variations:

Bicara lebih keras, tolong, agar nenek bisa mengerti. (more emphasis on the command)
Tolong bicara lebih keras, supaya nenek bisa mengerti. (comma with a pause in speech)

Starting with the agar-clause sounds more marked and less natural in everyday speech:

Agar nenek bisa mengerti, tolong bicara lebih keras.
– grammatically OK, but feels more formal/written or rhetorical.

The original order is the most natural for normal conversation.