语言学习者会经常遇到这样的问题：fill the gap vs fill in the gap，到底选哪个？此处介词in是必要的吗？

诸如此类语法、词汇选择、短语搭配的疑惑，可以通过查阅词典和语法书得以解答。但我们更希望有一个快捷、可靠的工具帮助我们找到答案。Linggle就是这样的一个工具。

Linggle 是由台湾国立清华大学自然语言处理实验室开发的英语语法和语言搜索引擎。它可以帮助确认单词的选择、用法和搭配，使您的写作更加自然。 其所提建议基于多个语料库，例如 Google Web 1T 5-gram、英国国家语料库（BNC）、纽约时报标注语料库（NYTAC）。

Linggle有Linggle Read、Linggle Write、Linggle Search三个工具。

本文主要介绍Linggle Search的用法。

Linggle Search 是一個奠基於大數據語料庫中的其語捜尋引擎，可藉由多元的查詢指令，針對任何單字、片語進行查詢，並分析使用頻率。

Linggle 提供了一些简单的搜索运算符，可让您快速找到这些单词在真实世界中的使用方式。

Common symbols

Linggle supports a few symbols while performing search.

/

Or: Any collection of words.

Examples:

it is a/an apple
receive/accept education
I come/came from/for/to school 

$

0 ~ many characters: Any length of characters.

Examples:

what are you $ing
I am a w$n
I love $melon 

_

1 word: Any single word.

Examples:

she is _
are you _ well
he _ a _ man 

*

0 ~ many words: Any number of words.

Examples:

do you *
* so hot
is * me 

~

synonyms: Any words with the same meaning.

Examples:

I am ~happy
I finished my ~homework
~take a photo 

?

Optional: Return results with/without the word.

Examples:

discuss ?about the issue
what ?is the problem
I ?am come from n. 

Part-of-speech (POS)

Linggle also supports POS tags for advanced usage.

v.

verb: Any verb (is, am, are, was, were, has, have, had, …)

Examples:

I v. you
v. a method
it v. my time 

n.

noun: Any noun (apple, banana, carrot, durian, …)

Examples:

I hate n.
n. is coming
n. is going to n. 

adj.

adjective: Any adjective (happy, sad, upset, angry, …)

Examples:

as soon as adj.
it is adj. for me
such a adj. day 

adv.

adverb: Any adverb (so, often, too, really …)

Examples:

it is adv. hard
as adv. as possible
they are doing adv. 

prep.

preposition: Any preposition (of, by, for, to, …)

Examples:

available prep. now
on top prep. it
a bottle prep. water 

det.

determiner: Any determiner (a, an, the, that, …)

Examples:

I look at det. book
when he was det. boy
at det. university 

conj.

conjunction: Any conjunction (and, but, so, or, …)

Examples:

I tried conj. *
between _ conj. _
it was * conj. 

pron.

pronoun: Any pronoun (he, she, it, them, …)

Examples:

look at pron.
pron. is beautiful
pron. said pron. v. adj. 

让我们通过下面的例子来探讨一下 Linggle 能为我们做什么。

对于文首的问题：fill in the gap中有必要加介词吗？

可以在浏览器中打开https://search.linggle.com，然后在搜索框中输入fill ?in the gap。此处单字节问号?表示其后所跟单词为可选项，即在语料库中检索所有含或不含in这个介词的短语。检索结果将包含fill in the gap和fill the gap这两个短语。根据二者出现频次，可以判断不加介词in的形式fill the gap更常见，出现了150,000次，而加介词in的形式fill in the gap则少见得多，仅出现了1,600次。二者比值为90.2%:9.2%。