Please help! Struggling to understand a few things about the particles- "ga" が and "wa"は

I started learning japanese about a week ago and have recently just spent a bit of time learning some grammar.
I understand all of this from this website- The difference between 「は」 and 「が」 | Tae Kim's Blog

Me) 食べた？ – Did you eat?
You) 食べた。 – I ate.

Now, what if I wanted to ask you if Alice ate? Then I need to use the 「は」 particle to indicate that I'm talking about Alice. Otherwise, you would just assume I'm talking about you.

Me) アリスは食べた？ – Did Alice eat?
You) 食べた。 – She ate.

Notice how once I establish Alice as the new topic, we can continue to assume that we are talking about her until someone changes the topic.

I also understand the usage of ga:

Me) 誰がチキンを食べた？ – Who ate the chicken?
You) アリスが食べた。 – Alice [is the one who] ate it.

Notice that the 「が」 particle is used twice because you need to identify who ate the chicken in the answer. You can't say 「アリスは食べた。」 because we're not talking about Alice. We're trying to identify the unknown person that ate the chicken.

My first question is If i then wanted to say "She (Alice) liked eating it (the chicken)" would I use は in this sentence? (surely you would because now we ARE talking about alice? Or could you omit は because its obvious we are talking about alice?)

My second question is if I used は instead of が in the "Alice ate it" sentence above would it not make any sense at all in japanese? Or would it make sense but just imply that others could have also been involved in "eating the chicken" as you are not using this が identifying particle?

Thanks for taking the time to help me! I'm probably over thinking it a bit

Grammar help | Japan Forum

勉強文 | Japan Forum

Thankyou your explanations in those threads have helped me a lot!

Also refer to the following site/thread.
The Difference Between the Particles "wa" and "ga" - 80/20 Japanese
を vs. は | Japan Forum

Troyston said:

My first question is If i then wanted to say "She (Alice) liked eating it (the chicken)" would I use は in this sentence? (surely you would because now we ARE talking about alice? Or could you omit は because its obvious we are talking about alice?)

Click to expand...

It totally depends on the context.

Troyston said:

My second question is if I used は instead of が in the "Alice ate it" sentence above would it not make any sense at all in japanese? Or would it make sense but just imply that others could have also been involved in "eating the chicken" as you are not using this が identifying particle?

Click to expand...

は works as the contrastive marker in that case, thus, it means "Alice ate it (but other person(s) than her, including the speaker, didn't)". In other words, Tae Kim's explanation "You can't say 「アリスは食べた。」" is also an example of "countless number of equally confusing (and sometimes wrong) explanations", or at least it's insufficient.

Toritoribe said:

Also refer to the following site/thread.
The Difference Between the Particles "wa" and "ga" - 80/20 Japanese
を vs. は | Japan Forum


It totally depends on the context.


は works as the contrastive marker in that case, thus, it means "Alice ate it (but other person(s) than her, including the speaker, didn't)". In other words, Tae Kim's explanation "You can't say 「アリスは食べた。」" is also an example of "countless number of equally confusing (and sometimes wrong) explanations", or at least it's insufficient.

Click to expand...

Ah I see, I've just read about using は as a contrastive marker so that make sense now. From Tae Kim's explanation I was under the impression that you could not use は in that context at all otherwise it would be completely grammatically incorrect and no one would understand you. Now i've realised that I could've used it and I would be implying the same thing just in a different way. Thanks for your answer!