Learn Hardcore Indonesian: Dia seharusnya menghubungi ibunya tadi malam, namun dia lupa. - He/She should have contacted his/her mother last night, however he/she forgot.

Seharusnya expresses expectation/obligation (ought to). Indonesian doesn’t mark past by verb form, so adding a time expression like tadi malam pushes it into a past expectation, which corresponds to English “should have.” You can make the past expectation even clearer with sudah/telah: Dia seharusnya sudah menghubungi ibunya tadi malam.

What’s the difference between seharusnya and harusnya?

They are near-synonyms; harusnya is more colloquial and shorter, while seharusnya can feel a bit more formal or moralistic. Both work here: Dia harusnya menghubungi ibunya tadi malam, … The meaning stays the same.

How can I emphasize the “should have (by then)” sense more strongly?

Add a completion marker like sudah or telah: Seharusnya dia sudah menghubungi ibunya tadi malam, namun dia lupa. This highlights that the action was expected to be completed by last night.

What’s the nuance difference among tadi malam, kemarin malam, malam tadi, and semalam?

All of tadi malam, kemarin malam, and malam tadi typically mean “last night,” with tadi malam being the most common. Kemarin malam is also widely used (literally “yesterday night”). Semalam can mean “last night” but can also mean “all night long,” so it can be ambiguous without context.

What does the suffix -nya in ibunya mean?

-nya marks third-person possession (“his/her”) or definiteness (“the”). In this sentence, ibunya most naturally means “his/her mother.” Context decides whose mother; if needed you can specify, e.g., ibu Budi or ibunya Budi.

Is ibunya dia correct?

It appears in some informal speech, but standard, natural Indonesian prefers ibunya (or ibu dia in certain styles). Ibunya dia is generally seen as redundant; stick with ibunya.

Why is it menghubungi and not menghubungkan?

Menghubungi means “to contact (someone),” while menghubungkan means “to connect (something to something),” e.g., connecting cables or ideas. Since the action is contacting a person, menghubungi is the correct verb.

How do menghubungi, menelepon/menelpon, and mengontak differ?

Menghubungi is broad: to contact (by call, text, chat, email, etc.).
Menelepon (standard; menelpon is common colloquial spelling) is specifically “to call (by phone).”
Mengontak is a colloquial borrowing (“to contact”), common in speech but less formal than menghubungi.

What is the verb formation of menghubungi?

Root: hubung. With prefix meN- (becomes meng- before h) plus suffix -i → menghubungi. The -i form typically takes the person/thing affected as the direct object, hence menghubungi ibunya.

Can I omit the second dia and just say …, namun lupa?

Yes. Indonesian often drops subjects when they’re understood from context: Dia seharusnya menghubungi ibunya tadi malam, namun lupa. Keeping the second dia is also correct and a bit clearer.

Can I use ia or beliau instead of dia?

Ia is a more formal subject pronoun; it’s typically used only as subject: Ia seharusnya menghubungi… namun ia lupa.
Beliau is a respectful form for an esteemed person (older/higher status): Beliau seharusnya… namun beliau lupa. Use it only when appropriate.

Is dia gendered?

No. Dia is gender-neutral. If you need to clarify gender, you add context (e.g., a name) or explicit nouns like laki-laki or perempuan, but that’s rarely necessary for pronouns.

Is the comma before namun necessary? And how do namun, tapi, tetapi, akan tetapi differ?

A comma before namun is standard and helps readability. Register differences: tapi (informal), tetapi (neutral/formal), namun (formal, often like “however”), akan tetapi (very formal). All can work; pick based on how formal you want to sound.

Can I change the word order?

Yes, Indonesian is flexible with adverbs and stance markers:

Seharusnya dia menghubungi ibunya tadi malam, namun dia lupa.
Tadi malam dia seharusnya menghubungi ibunya, namun dia lupa.
All are natural; fronting tadi malam or seharusnya just changes emphasis slightly.

Is Dia lupa menghubungi ibunya tadi malam acceptable, and is the nuance the same?

Yes, it’s natural. Dia lupa menghubungi… centers the act of forgetting; the original sentence with seharusnya … namun … highlights the failed expectation and then contrasts it with forgetting. Both convey the same overall outcome.

Difference among lupa, melupakan, kelupaan, and terlupa?

Lupa = forget (intransitive or with a verb complement): Dia lupa; Dia lupa menghubungi…
Melupakan = to forget something/someone as a direct object, often long-term or intentional-sounding: Dia melupakan janji itu. Not used with verb complements.
Kelupaan = accidentally forgot (colloquial): Dia kelupaan menghubungi…
Terlupa exists but is formal/rare in everyday speech.

Do I need untuk after seharusnya?

No. After seharusnya/harusnya, use the verb directly: seharusnya menghubungi, not seharusnya untuk menghubungi. Using untuk there sounds unidiomatic.

Could I show respect to the mother in the object position?

Yes, if you want to be respectful toward the mother, you can use beliau as the object: Dia seharusnya menghubungi beliau tadi malam, namun dia lupa. Alternatively, specify the relationship respectfully: Dia seharusnya menghubungi ibu beliau tadi malam.