We met the adverbial noun よう previously when we looked at ways to express similarity in Japanese. Its other grammatical usage is to express a change of state from A to B.
|To become to have an interest in tennis.
Essentially all we are doing is modifying the adverbial noun よう to describe the “state” or “condition” and then appending the verb “to become” to express the change.
While not grammatically incorrect this structure is rarely ever used with the negative. Instead, the negative verb is treated as as an i-adjective, turned into an adverb, and appended with the verb “to become”.
|～ないようになる ⇒ ～なくなる
|You see, he stops crying if you give him a toy.
よう very often used with the potential form of the verb to express that someone has “become able to do” something.
|To become to be able to do.
|After I came to Japan I’ve been able to use chopsticks well.
The literal translation “to become to be able to” does not always sound natural in English; whereas the Japanese grammar makes clear that there has been a change of state.
|As smartphones have become prevalent we’re able to transfer money through just an app.
|If you study political history you will understand the background to current issues.
And remember that よう is an adverbial noun so we can modify other nouns with the な particle as we would with a na-adjective.
|I’ve already had a drink and so I’m not in a condition to drive.
|He’s not a guy you can trust, right?
However, this structure cannot be used with the negative. As we have seen before, the final い of the standard negative form of the verb is treated as an i-adjective, turned into an adverb, and appended with the verb “to become”.
|To become to be not able to do.
|You won’t be able to run long distances once you get older, you know.
|I’m not able to leave my house due to heavy snow.
|Recently I’m put on a little weight and I can no longer wear one of my favourite dresses.
よう can also be used with verbs other than なる. This way we can show that a change was instigated by someone (as opposed to it being a natural consequence of an event).
|Instruct someone to arrive at work for 8am the following day.
With the negative we must use the structure with よう.
|Please lock the door so that people will not enter.
|Please do not forget to take home any valuables.
|Get an immunization shot to prevent catching influenza.
Note how we can change the ending verb to make more complex sentences.
|Today I’ll make it so that I can go home early.
|Today I’ll try hard so that I can go home early.
|Today I’ll work while eating lunch so I can go home early.