Why is 到 necessary here?

Question

I think I have ever asked this question once but not in a detailed way.

Sentence :

今天的考试要((用到))词典，请大家把词典也放在桌子上

I wonder why they put 到 after 用... I know 到 is used as a result complement BUTTT what kind of result does it try to indicate here?

Answer 1

Combination of a verb with 到 generally implies some sort of "finished" state, in an sense it's similar to some sort of perfect tense:

• 我 走到 公園 / I walked to the park
• 我 吃到 炸雞了 / I finally ate that fried chicken
• 在字典裡 查到 這個字了 I found this word in a dictionary

Without the suffix "到", the verb along could be "unfinished"

• 我 走去 公園 / I walk to the park
• 我 吃 炸雞了 / I ate fried chicken
• 我在字典裡 查 這個字了 I looked this word up in a dictionary

Now back to your example:

今天的考试要用到词典，请大家把词典也放在桌子上

Notice that "今天的考试" is not the subject of the verb "用到" -- since the "exam" would not be the user of a dictionary. The user of that dictionary is "大家". Alternatively that sentence can be rephrased to be:

今天的考试，大家要用到词典，请把词典也放在桌子上

I'd translated this to

Each one of you will be using a dictionary in the exam today, please also put it on the table.

Now if we remove "到"

今天的考试，大家要用词典，请把词典也放在桌子上

IMHO it can be translated into something like any of these:

1. Everyone intends to use a dictionary...(omit)
2. Everyone is asked to use a dictionary...(omit)
3. Everyone must use a dictionary...(omit)

In a sense, adding "到" disambiguates from these different contexts -- well, usually appending more modifiers disambiguates better... :)

Now that was a different example then whan you provided, and I admit that it is a bit of a streatch. Let's revisit this one without the "到":

今天的考試要用词典

If I must not insert an auxiliary subject into the sentence for translating, it is almost tempting to come up with something like:

1. The exam today will use a dictionary
2. Today's exam will use a dictionary

(Translating word-by-word. A pretty common thing being done by many English learners)

Overall the call-to-action is not differ and pretty clear -- dictionary on the table! -- but that's because the options are pretty limited.

Answer 2

到 http://www.cantonese.sheik.co.uk/dictionary/characters/673/

[particle] used after a verb to indicate attainment/achievement or potentiality

到 in this sentence indicate potentiality

今天的考试要用词典，请大家把词典也放在桌子上 - In today's exam, you have to use a dictionary, please put your dictionary on the table as well.

you have to use a dictionary/ you need to use a dictionary

~

今天的考试要用到词典，请大家把词典也放在桌子上 - In today's exam, you would have to use a dictionary, please put your dictionary on the table as well.

词典 is a potential item that's chosen to be required

If the sentence was "今天的考试要用到词典和计算器" then dictionary and calculator are the two potential items that are chosen to be required

If the sentence was "今天的考试要用到词典但用不到计算器" then dictionary is a potential item that's chosen to be required, while calculator is a potential item that's not chosen to be required

Similar example:

鎮壓示威要用武力 Repression of demonstrations requires the use of force

(武力 is the only solution)

鎮壓示威要用到武力 Repression of demonstrations would requires the use of force

武力 is a potential solution that's chosen to be used

Answer 3

You could say 要用词典 and there is nothing wrong with it, and to me it means almost exactly the same, but when you say 用到, the emphasize goes slightly towards 词典.

So the result it tries to indicate is that "a dictionary is used". It's different with other cases such as 想到借口 and 申请到护照 because in latter cases, the result is something that follows the action, but in the case of 用到词典, the result is the action itself.