Adakah ini jenama teh yang kakak saya suka?

to like

Breakdown of Adakah ini jenama teh yang kakak saya suka?

• ini: this
• saya: my
• kakak: the older sister

Questions & Answers about Adakah ini jenama teh yang kakak saya suka?

What does adakah do in this sentence?

Adakah is a formal question marker for yes/no questions. It does not have a single direct English translation, but here it helps create the sense of Is ... ?

So:

Adakah ini jenama teh yang kakak saya suka?
= Is this the tea brand that my older sister likes?

In everyday spoken Malay, people often leave out adakah and rely on intonation instead:

Ini jenama teh yang kakak saya suka?

That sounds less formal and more conversational.

Why is there no separate word for is?

Malay often does not use a verb like English to be in sentences of identity or classification.

So instead of saying something like This is a tea brand, Malay can simply say:

Ini jenama teh.

Literally, that is closer to This tea brand, but it naturally means This is a tea brand.

In your sentence, adakah marks the whole sentence as a yes/no question, so Malay does not need a separate word for is.

What does yang mean here?