Why doesn't tell need a preposition in sentences like the following?
I told him. ＝ Isubject toldverb <why no preposition> himobject
I think it has something to do with it being an action verb but I'm not sure.
Learn English – When does the verb “tell” need a preposition and when doesn’t it
prepositions
Related Solutions
It doesn't need a preposition, but the main clause might need a different one, depending on the context.
I think it should be on 9 o'clock but I can't guarantee it.
You don't need to write (or say) 9:00 o'clock, it's redundant.
Also, guarantee is a verb in this case; my understanding is that guaranty may be used only when it is a noun. Here, you are saying that you cannot promise that it should be on 9 o'clock.
Try something like:
I think by 9 o'clock, but I can't guarantee it.
The implication is that you are saying:
I think [we should leave] by 9 o'clock, but I can't guarantee [that that is correct]
The conventional rule for indirect objects is that the preposition can be omitted if the indirect object goes between the verb and the direct object:
I gave the message to him - verb-direct-to-indirect
I gave him the message - verb-indirect-direct
What's happening in the first sentence is that there is a relative clause with the relative pronoun that. In spoken English, the relative pronoun can be omitted: here is your first sentence as it would be written in formal English, with the relative pronoun included:
Open the file that I sent (to) you.
In the second sentence, what is acting like a pronoun that represents the direct object.
In both cases, then, the direct object is a pronoun at the front of the clause, so the indirect object cannot go between verb and direct object. When parsing the sentence, we understand that the direct object has been fronted, so it's OK to omit the preposition even though we just have verb + indirect object. One of the answers to this question confirms that the omission is permissible.
Note that it is also OK to omit the preposition for, for example:
He ate the sandwich that I made for him
He ate the sandwich that I made him
Note that, if the relative pronoun is used to represent the indirect object, the preposition cannot be omitted. In some cases, you end up with a dangling preposition:
the girl that I lent my jacket to
the person that I poured a drink for
I don't know the man to whom you sold the house
Note that, in very informal spoken English, you may hear the preposition omitted from sentences like the first one. You may also hear final sentence produced incorrectly, but in this case the to is never omitted:
I don't know the man who you sold the house to
Best Answer
You actually have the question backward! :) ... you should be asking When does an Indirect Object require a preposition?
(For those unfamiliar with the term, an Indirect Object is a secondary object of a transitive verb: it designates the entity which receives the Direct Object or for whose benefit the action is performed on the Direct Object.)
This construction is the standard order in all di-transitive situations—those in which the verb takes both an Indirect Object and a Direct Object.
Sometimes, however, the Indirect Object has to fall after the Direct Object. When that happens, the syntactic relationships are no longer clear, so the Indirect Object is ‘marked’ with a preposition. There are two circumstances when this happens:
When the Direct Object is a single pronoun it is too ‘light’ for its role to be clear, so it is moved immediately after the verb:
When the Indirect Object is ‘heavy’, more than a couple-three words long, it draws focus for too long and it makes it difficult to recognize the Direct object, so it is moved after the Direct Object:
These ‘heavy’ Indirect Objects may not seem all that hard to process; but that is because you are encountering them in writing, where you have the advantages punctuation to clarify structure and of seeing the entire sentence at once. In speech, where your hearer must process your sentence as it emerges, it isn’t so easy, and these constructions are driven by speech patterns.
Two general “rules” are operating here.
The first is that we like to keep the core constituents of a sentence—the Subject, Verb, Indirect Object and Direct Object—as close together as possible. That drives ‘heavy’ constituents towards the right end of the sentence, where their length provides the least interruption.
The second is that we like to put the ‘new’ information in a sentence at the right end. That drives pronouns towards the left, because pronouns are almost always ‘old’ information—they usually refer to entities which have already been introduced.