Ga

If I understand correctly, the differences between ha, ga and wo are such :

It is often taught as though ha is used not to determine the subject, but the "theme" of the sentence when it is not clear from the context what is being talked about. Like "concerning this …" and then the actual sentence takes place. So it could be used like "Ashita (ha) isogashiku nai." Which would be "concerning/about tomorrow, I'm not busy."

Sometimes it can be confusing if the word associated to ha can be a subject in an english sentence, like : "Ashita (ha) isogashiku nai. Anata ha hataraku ?" Which would then be: "About tomorrow, I'm not busy. What about you, do you work ?" The idea is that, in japanese, you don't have to say things that are already understandable from the context. So, in the first sentence, ha is necessary to let the interlocutor know they are now talking about tomorrow. Without it, it wouldn't be obvious if the person is talking *about* right now or, if not, *about* when. It would simply be "Isogashiku nai." "I'm not busy."

In the second sentence, the speaker changes the focus from himself to the interlocutor. They were talking *about* him, now he wants to know *about* you. So it's still not a subject. The "Anata ha" here literally means "about you". So with the tone of a question "Anata ha ?" becomes "What about you ?" Technically the sentence could end here "Ashita, isogashiku nai. Anata ha ?" "Tomorrow, I'm not busy. What about you ?" But it is truly when something like a verb is added that it becomes confusing.

Here with "Anata ha hataraku ?" it could give the impression that anata is the subject if one tries to understand japanese in an english way seeing "you ha work ?" But it is not. A verb doesn't necessarily need a subject. Ha simply explains that we are now talking about you. Once it is said, the speaker asks then if you work. The two things aren't directly related. In fact, as much as you can say "Anata ha ?" "(What) about you ?" alone, you can also say "Hataraku ?" "(Do you) work ?" alone just as well.

Whereas ga (in one of its uses) and wo are really used to link words to verbs as subjects or objects.

"Ashita (ha) isogashiku nai. Anata ha hataraku ?
-Iie, hataraka nai. Demo, youji ga aru."
"Concerning tomorrow, I'm not busy. What about you, are you working ?
-No, I'm not working. But, there are (exist) things (youji = things/errands/chores/etc. that I need to do)."

Some verbs, like "aru" here, need something linked to it directly. When you say "aru", "be/exist", *something* exists. In this case it's "youji", "an errand or something" and you use ga to specify it, making it the subject/direct object.

So, the difference between ha and ga/wo is simple. Ha changes the focus of the conversation, so that everyone knows what you are talking about, the context, the "theme" and ga/wo actually links verbs (or adjectives) to the words they need to make sense. Ha configures the sentence/conversation, ga/wo goes with the verb specifically.

Now the difference between wo and ga is a little tricky. Wo is used to make something the direct object of a verb : "Ringo wo taberu.", "I eat an apple." And it could feel exactly the same as ga : "Ringo ga aru.", "There's an apple.", but the difference lies in if the verb is an action or passive. Eating is an action, therefore wo should be used, but the existence of something isn't an action, it is just the way it is, it's passive, so ga should be used.

That's why ga is used with verbs (and adjectives) like : understand, be/exist, like…
"Sakana ga suki.", "I like fish". Liking fish isn't an action, it's a fact, so, ga.
"Eigo ga wakaru.", "I understand english". It is not an action either. Practicing it or studying it would be an action, but not understanding it. It is just the way it is.

And that's why wo is used with verbs like : eat, drink, study, read…
"Biiru wo nomu.", "I drink beer."
"Nihongo wo benkyousuru.", "I study the japanese language."
"Hon wo yomu.", "I read a book".

Is that right ?

Would you use が for any たい ending verb?

Thank you Mr. Yuta!

Thank you so much. Your explanations are clear and very helpful. Greetings, an Austrian beginner

It would be interesting if you make a video showing when a particle can't be supressed.

To be honest, I find this video biwildering. The fact that in the expression "A likes B" A is the subject and B is the direct object only depends on the specificity of the English verb "like". In other languages, to express the same concept, the structure of the sentence is totally different because the verbs behave differently. I'm thinking of "piacere" in Italian, "plaire" in French, and "gustar" in Spanish: in all these instances, B is the subject of the verb and A a complement.
As a consequence, I do not why I should expect A to be the subject of the Japanese expression conveying the same meaning, especially given the fact that 好き is an adjactive and so should rather require a copular verb construction, more akin to the (oddly sounding in English) "B is likable to A".
I believe that providing an example were the speaker is not part of the sentence would make the construction clearer.
Possibly this would also explain why one can use both が and を with 見たい?

Thanks for you lesson, Yuta-sensei.

dear,yuta sensei,

are you able gonna make other video explaining other particles beside は and が?

Okay, so I see that Television is said first in the sentences … it makes me curious as to what the sentence structure is. Normally for english it is Subject-Verb- … and then there can be (adj, adv, object, ect.).

In Japanese with so much being implied, and the object and such being first, what is the typical Japanese sentence structure?