untuk

The word untuk is essential for connecting actions to their goals, recipients, or functions. The main uses taught here are purpose, benefit, and intended use; other dictionary senses also exist.

1. Expressing Purpose
When followed by a verb, untuk explains the reason for an action. Crucially, an untuk purpose clause usually cannot introduce a new, overt subject for an active verb. The implied subject must be controlled by someone already mentioned in the main sentence. However, you can use a pronoun after untuk if it acts as the agent in an object voice construction (e.g., 'Kue ini untuk kamu makan' - This cake is for you to eat). If you need to introduce a new subject for an active verb (e.g., 'I cook so you can eat'), you must use agar or supaya.

2. Expressing a Beneficiary (For someone)
When followed by a noun or pronoun, it indicates who the object or action is intended for. It can also attach to short pronouns:

• Untukku (for me)
• Untukmu (for you)
• Untuknya (for him/her/it)

3. Expressing Intended Use or Function
When describing what an inanimate object is used for, untuk connects the object to its function (e.g., 'kamar untuk tamu' - room for guests, or 'sabun untuk mencuci baju' - soap for washing clothes). Note that untuk is frequently dropped to form compound nouns (e.g., 'kamar tamu' - guest room, 'sabun mandi' - bath soap).

4. As a Verb Complement (The Infinitive "to")
Untuk is heavily used as a complementizer to connect a main verb of intention, decision, or command to a secondary verb, acting like the English infinitive "to" (e.g., 'Dia memutuskan untuk pindah ke Bali' - He decided to move to Bali).

5. As for / Regarding
At the beginning of a sentence, untuk is often used to introduce a topic, meaning 'As for' or 'Regarding' (e.g., 'Untuk masalah ini, kita harus...' - As for this problem, we must...). This is related to topic framing with untuk.

6. Register Differences and Alternatives

• Untuk: Standard and neutral for all contexts.
• Agar and Supaya: These mean 'in order to' or 'so that'. They can replace untuk only in purpose clauses, not when expressing a beneficiary or function. Agar is more formal, while supaya is neutral.
• Buat: The primary informal/colloquial replacement for untuk in daily conversation.
• Bagi: Used in formal contexts to mean 'for' when expressing a perspective (e.g., 'Bagi saya...' / 'For me...').

In daily conversation, untuk is often omitted entirely before a verb (e.g., 'Saya ke pasar beli ikan').

7. Time Expressions
For a straightforward statement of how long an activity lasts, selama is a clear, useful model (for example, Saya tinggal di sini selama dua tahun). However, it is incorrect to ban untuk from all time expressions: KBBI records a duration sense equivalent to selama. It also occurs with an intended or allocated period, as in kontrak untuk dua tahun (a contract for two years). Choose the preposition according to the intended meaning and context, rather than mechanically translating every English for the same way.