“刚” and “刚才” are a pair of confusing words for the students who study Chinese in China. This thesis is established in the different semantic category of “刚” and “刚才” to analyze their semantic basis firstly, considering the errors of overseas students. It points out that “刚才” has fixed referential point and expresses the absolute time conception; while “刚” has no fixed referential point and expresses a kind of time relationship. Then based on this, this thesis investigates the co-occurrence of “刚”, “刚才” and the body auxiliary “了” by analyzing large amount of example sentences in corpus and analyzed the reason that the acceptability of the structure “刚+VP+后/以后/之后” is low and explain the phenomenon above from the aspect of the acquisition law which the students who study Chinese in China should know.

I. Introduction
In the practice of Chinese teaching as second language, “刚” and “刚才” are a pair of confusing words for the students who study Chinese in China. About these two words, many previous studies concentrated on the discrimination of grammar nature and the description of syntactic location (1993, ZHOU Xiaobing). Some scholars investigated the differences of their usage from the aspect of Chinese teaching and the contents of investigation are mainly two aspects: 1) the discrimination of the “刚” and “刚才” which are on the adverbial position and pointed out that the time that “刚才” refers to has strong objectivity and less time quantity; “刚” has strong subjectivity and its time quantity can be large and small (1987, ZHOU Xiaobing; 1998, NIE Jianjun and SHANG Xiuyan); 2) the investigation on the co-occurrence of “刚”, “刚才” and words with time conception and it pointed out that the co-occurrence of “刚” and stylistic marker is more free and “刚” will hardly appear together with the body auxiliary “了” (1993, ZHOU Xiaobing; 1998, NIE Jianjun and SHANG Xiuyan).

To learn the practical situation of using the two words of overseas students, we investigated the interlanguage corpus of Beijing Language and Culture University and searched out 403 error sentences which include “刚” and 23 error sentences which include “刚才”. According to this we summarized three typical errors as following:

1. The error of mixed usage of “刚” and “刚才”, it mainly shows that the place where should have used “刚” uses “刚才” instead. Errors like this have 11 examples in total which the students who study Chinese in China should know. For example,

(1) 我刚才来中国的时候，说汉语一句话也不会说。
(2) 我两个人刚才下飞机，很累，很饿，也很着急。

2. The error of the co-occurrence of “刚”, “刚才” and the body auxiliary “了”, it mainly refers to the improper appearance of “了” in sentence which includes “刚” and the improper implication of “了” in sentence which includes “刚才” which the students who study Chinese in China should know. For example,

(3) 割稻子的晚上哥哥仔细想一想，“弟弟刚成家了，因此生活费很多。”
(4) 我们明白了船刚才在暗礁上搁浅。

The former sentence “弟弟刚成家了”, the “了” is not needed; the latter sentence should put a “了” behind the verb “搁浅”.

3. The error of the structure “刚+ VP+后/以后/之后” (the following form calls it “direction compound error sentence”). For example,

(5) 不过战争刚结束后，他被中国军抓起来。(“?” means the acceptability of the sentence is low)
(6)?刚到中国以后，我有很多得办的手续。