Some things are easy to understand, others are hard to understand. Some people are hard to talk to, others easy to talk to. Learn how to say sentences like this in Japanese, using yasui and nikui with any verb.
Easy or Hard to Do
In English, we often describe something as easy or hard to do. This book was easy to read, that person is difficult to talk to. These are very common sentences, and are very useful when you want to describe something. The pattern we use in English is:
easy/hard + to + [verb]
It's a fairly straightforward structure in English. Learning the same grammar pattern in Japanese is fairly easy as well, and it uses an equally simple structure.
The Grammar Structure
If you look at the English pattern, there are two main parts, the "easy/hard" and the verb itself. The first part to learn is the words for easy and hard in Japanese. The words used in this grammar pattern are yasui (easy) and nikui (hard). At this point, we only have the verb left. As with many Japanese verb patterns, we have to change the form of the verb. This particular form is very simple to create. We need what is called the "stem" of the verb, and we get this by conjugating the verb in the -masu form, and then removing the -masu. A few examples:
verb | -masu form | verb stem
taberu | tabemasu | tabe- (to eat)
nomu | nomimasu | nomi- (to drink)
iku | ikimasu | iki- (to go (to))
suru | shimasu |shi- (to do)
Any verb that you can conjugate into the -masu form can give you the stem by removing -masu, there are no exceptions. At this point, to say "easy to [verb]", you simply add -yasui at the end. To say "hard to [verb]", you add -nikui. The basic pattern in Japanese is as follows:
[verb stem] + yasui/nikui
Here are the same verbs again, but in the easy/hard to do forms:
verb (-masu form) | easy to [verb] | hard to [verb]
tabemasu | tabeyasui | tabenikui
nomimasu | nomiyasui | nominikui
ikimasu | ikiyasui | ikinikui
shimasu | shiyasui | shinikui
Those verbs translate to "easy/hard to eat", "easy/hard to drink", "easy/hard to go [to]", and "easy/hard to do." Notice that the major difference is that in English, the easy or hard comes before the verb, whereas in Japanese, it comes after, as part of the verb.
Using it in a Sentence
Now that you have this structure down, how do you use it? Because the new verb ends with the adjective yasui or nikui, it is treated like an adjective, and is a regular -i adjective. Any pattern where an -i adjective can be used can be applied to this structure. Here is an example:
Kono hon wa yomiyasui desu. (This book is easy to read)
You can see the typical subject + wa + adjective + desu structure used with any adjective, such as "red" or "expensive." In this case, however, we have the adjective "easy to read," which we obtained from the verb yomu (to read) and the adjective yasui (easy to do). Here are a few more examples, along with translations. Try to see how the pattern was formed in each, and figure out the base verb used.
Watashi no sensei wa hanashinikui desu. (My teacher is hard to talk to)
Ano tsukaiyasui konpuuta wa takai desu. (That easy to use computer is expensive)
Kankokugo no eiga wa wakarinikui desu. (Korean movies are hard to understand)
Ookii hanbaagaa wa tabenikui desu. (Big hamburgers are hard to eat)