One very important piece of grammar that you will want to learn quickly is how to say want. To do this you will need to conjugate your verb and tack on たい to the end. However, the たい itself can be conjugated to signify that you wanted, did not want, or even simply don’t want. It may appear to be a complicated process but if you have already learned basic verb conjugations as well as how to conjugate your adjectives, it will be a piece of cake.
For example 食べる would become 食べます, we then drop the ます to make 食べ and finally add the たい.
At this point you may be wondering why bother forming the ます at all. Why not simply just drop the る? Unfortunately, you may remember from our basic verb conjugation lesson that not all verbs make the ます form the exact same way. う verbs require you to change the last hiragana into its い tense before you add the ます.
So 書く becomes 書きます. To then form the たい form we then simply drop the ます to make 書き and add たい at the end to make 書きたい.
走る becomes 走ります, drop the ます to form 走り and add the たい to make 走りたい.
The last little bit to talk about is the verb する. If you remember correctly する changes into します when conjugating into the ます form. It is the same when saying you want. Drop the ます and you get し add the たい and you get したい.
But what if you wanted to indicate past tense? Well that’s pretty simple if you remember how to conjugate い adjectives. It is best to look at たい just like you look at ない, as an い adjective that is conjugated by dropping the い and adding かった.
In the case of 食べたい, you drop the い and add a かった to make 食べたかった. It can be a bit tough to say, but after a bit of practice you will get it down.
Let’s look at a few more examples.
遊ぶ (あそぶ) becomes 遊びたい and then 遊びたかった to indicate the past tense of I wanted to play.
勉強する (べんきょうする) becomes 勉強したい which then gets conjugated into 勉強したかった or I wanted to study.
Now that you have the present and past tenses down, let’s look at their negative forms.
To say that you do not want to do something, you simply need to conjugate the たい exactly how you would an い adjective in its negative form. To do this you will drop the い from the たい and add くない.
So 食べる becomes 食べたい to say I want to eat. To then make it negative you drop the い and add くない to make 食べたくない.
走る becomes 走りたい which then becomes 走りたくない.
やる becomes やりたい which then becomes やりたくない.
The last aspect of the たい conjugation is making the negative form in the past tense. Once again this is really simple if you already have your い adjective conjugations down. You will drop the い off the ない at the end of your verb and add かった.
So 食べたい becomes 食べたくない which then becomes 食べたくなかった.
走りたい becomes 走りたくない which finally becomes 走りたくなかった.
勉強したい becomes 勉強したくない which then becomes 勉強したくなかった.
Once again, forming these I want to sentences is simple if you know your い adjective conjugations, however there is a whole lot more to cover when saying I want in Japanese.
These are all very important, but now we are going to focus on how to say that we want other people to do something. I want him to come home. I want her to eat this. We do this by combining the て form of a verb with ほしい.
This ほしい can also be looked at as an い adjective and is conjugated like:
This can be a complicated grammar point to use if you have a smaller Japanese vocabulary, but 頑張ってください！
I want you to tell me how to get to the bank.
I want you to buy a guitar.
The final way to use ほしい is to simply say that you want something by adding がほしい after the thing you want.
I want a guitar.
I want cake.
I want someone to talk with.
Remember that if you are saying you want something you will use がほしい, but if you want to do something you will need to add たい to your verb.