dengan + Adjective

This construction is one of the primary ways to form manner adverbials in Indonesian, functioning similarly to the English suffix -ly.

• Structure: Verb + dengan + Adjective. For transitive verbs, the structure is Verb + Object + dengan + Adjective (e.g., Dia menutup pintu dengan pelan). Note that the adverbial phrase can also be moved to the beginning of the sentence for emphasis (e.g., Dengan cepat, dia lari).
• Comparison with secara: Dengan is broadly used for physical, emotional, and mental manner (e.g., dengan cepat, dengan gembira, and dengan teliti). When using dengan + an emotion adjective (like dengan gembira or dengan sedih), it describes the state of the subject while performing the action rather than just the mechanical manner of the verb. Secara + adjective often sounds more analytical, technical, or categorical (e.g., secara otomatis), but this contrast is a tendency rather than a hard grammatical boundary.
• Register and Omission: In casual conversation, the 'dengan' is often dropped if the adjective follows the verb directly, or speakers use adjective reduplication (e.g., pelan-pelan). However, dropping dengan when a direct object is present can cause ambiguity, making the adjective seem like it modifies the noun instead of the verb (e.g., memukul meja keras sounds like 'hit the hard table' rather than 'hit the table hard'). It is also grammatically correct and common to combine dengan with a reduplicated adjective for emphasis (e.g., dengan pelan-pelan, dengan hati-hati). Furthermore, even in formal Indonesian, certain common verb-adjective pairings conventionally omit dengan (e.g., bekerja keras, belajar keras).
• Important Exceptions and Alternatives: For a basic statement about eating a large quantity, use makan banyak. Adding dengan does not express that same quantity model. Note that dengan is still perfectly fine when acting as a preposition modifying a noun phrase (e.g., makan dengan banyak orang). Additionally, for emotions, a frequent stylistic alternative is using dengan penuh followed by an abstract noun (e.g., dengan penuh kesabaran, dengan penuh kegembiraan).
• Negation: Generally, you can negate the main verb using tidak. However, negating the adjective inside the dengan phrase is a productive pattern used to mean 'in a non-[adjective] manner' or 'without [adjective]' (e.g., dengan tidak sengaja, dengan tidak sabar, dengan tidak adil). Alternatively, you can express negated manner using tanpa followed by a noun (e.g., tanpa kesabaran for 'without patience').
• Forms with -nya: Some manner phrases contain the attached form -nya to the adjective (e.g., dengan cepatnya). Interpret the emphasis or nominalized quality in context; -nya is not required in the basic dengan cepat pattern.

Optionality Has Limits: Ayo jalan dengan cepat and Ayo jalan cepat can both be useful choices. TBBI also accepts perlahan-lahan with or without a preceding manner preposition. That does not mean every manner preposition can be dropped: its formal model contrasts menjawab pertanyaan itu dengan tegas with an unacceptable bare tegas after that object.