को or no को for direct objects

Hindi marks some direct objects with को and leaves others unmarked. A known person normally takes को—मैंने राहुल को बुलाया “I called Rahul”—while an ordinary inanimate object usually does not—मैंने दरवाज़ा खोला “I opened the door.” Between those poles, को lets the speaker present an object as animate, identifiable, strongly affected, or contrastively selected.

This system is called differential object marking. It is not equivalent to English the, and को is not simply an “object word.” For the full syntax, see differential object marking with को.

The decision tree

Use this practical sequence:

1. Is the object a personal pronoun or a particular person? Use को or the fused pronoun form: मुझे, उसे, उन्हें.
2. Is it a particular animate being, especially a pet or personified animal? को is strongly favored.
3. Is it a nonspecific human role or animal kind? Both marking patterns can occur; ask whether the speaker means a particular referent or merely seeks an instance of the type.
4. Is it inanimate? Leave it unmarked by default. Add को only when the object is strongly individuated, contrasted, or construed as the bounded target of the action.
5. Is the phrase actually a recipient, experiencer, or goal? Then को may be required, but that is not direct-object marking.
6. Is the verb perfective with a ने-marked agent? Remember that a को-marked object cannot control agreement; the predicate normally takes default masculine singular.

The first object is a named person and requires को. The second is an ordinary inanimate patient and is naturally unmarked. English puts both immediately after the verb; that shared English word order tells you nothing about Hindi marking.

Particular human objects take को

Names, demonstrative human phrases, and contextually known people are normally marked.

Pronouns use conventional combined forms rather than a direct pronoun plus a separately written को: मैं → मुझे, तुम → तुम्हें, वह → उसे, वे → उन्हें. Respectful आपको remains visibly segmentable. A personal object without the appropriate form sounds incomplete or changes the syntactic analysis.

Nonspecific human roles: a real contrast

A profession or role can be presented as a type sought for a task, or as an identifiable individual. Hindi may distinguish those construals.

With verbs such as बुलाना, an unmarked occupational noun can have an existential “get/call someone of that kind” flavor in suitable contexts, whereas उस ... को unmistakably selects a known person. This is not absolute free variation: once a particular human is established, omitting को is generally nonstandard.

Animals: animacy follows the speaker's construal

A particular pet behaves much like a human object. A nonspecific animal, especially as a kind or food-source referent, is more likely to remain unmarked.

The vocabulary and event are nearly constant. Indefinite एक कुत्ता introduces an animal; possessive पड़ोसी के कुत्ते को identifies a familiar individual. Speakers can mark an indefinite animal when it is salient or affected, so the contrast is a strong tendency, not a ban.

Inanimate objects: unmarked is the default

Definite inanimate objects often remain unmarked. English the is the cue that most often misleads English-speaking learners: the book does not automatically become किताब को.

The demonstrative वह already makes किताब definite, yet no को is needed. In perfective clauses, the unmarked feminine objects control पढ़ी and रखी.

Marking an inanimate object becomes natural when the speaker singles it out against alternatives, treats it as the bounded target of an operation, or resumes it as a discourse topic.

Here को supports contrastive selection. The second sentence chooses one file for a different treatment. It does not establish a rule that all definite files require marking.

Agreement changes with the choice

In a transitive perfective, an unmarked object may control gender and number agreement. Once को marks that object, it is no longer an eligible controller, so the predicate normally appears in default masculine singular.

The semantic content overlaps, but the construal differs. Unmarked कहानी permits feminine पढ़ी. Marked कहानी को is singled out and produces default पढ़ा, not पढ़ी. Case marking and agreement are two surfaces of the same syntactic choice.

को may mark something other than a direct object

Do not use the presence of को alone to label a phrase “direct object.” It also marks recipients, goals, experiencers, and scheduled time.

Here रीना को is the recipient; unmarked चाबी is the direct object and controls feminine दी. In मुझे ठंड लगी, मुझे is an experiencer. The choice page concerns only direct objects, but recognizing these other functions prevents false agreement predictions.

A dialogue where the choice matters

डॉक्टर को refers to the already identifiable doctor upstairs. In a different context, डॉक्टर बुलाइए can naturally mean “Call a doctor,” requesting someone with that professional role. The marked form can also sound more direct toward the known individual; the unmarked role reading may be inappropriate if everyone knows exactly which doctor is meant.

Diagnostic checklist

• Is the object a pronoun or a specific human? Use को.
• If it is an animal, is it a known individual or treated personally? Favor को.
• If it is inanimate, is there real contrast, topicality, or affectedness? Otherwise leave it unmarked.
• Did English the influence you? Definiteness alone does not require को.
• In a perfective ने clause, did you adjust agreement after marking the object?
• Could the को phrase instead be a recipient, goal, or experiencer?

Common Mistakes

Both corrections are grammatical, but they package the object differently. Unmarked वह किताब controls feminine पढ़ी. Individuated उस किताब को requires oblique उस, and को blocks object agreement, producing default masculine singular पढ़ा.

Key Takeaways

• को is expected with pronouns and particular humans, favored with individuated animates, and optional only in a meaningful middle.
• Inanimate objects normally remain unmarked even when definite; contrast and affectedness can motivate को.
• English direct-object position and the are not reliable cues.
• A को-marked direct object cannot control perfective agreement.
• Recipient and experiencer को belong to different syntactic frames, even though the form looks identical.