Hello again, just like I did in the は vs が thread, I'm moving on to が vs が vs も available here. The mistakes I want to address are: #3, 4, 12, 14, 15, 16, 18, 20, 22, 23 & 30. So again, I provided the context here. #3: あれ「が」二百円ですか？I initially put は there. I guess it was a topic refocus but come to think about, also pronouns are used, they're essentially referring to the same thing. This isn't a topic refocus since it's the same as the previous line. I'm thinking this is a case of: "が marks the subject of a sentence when the information expressed as a subject is first introduced in a discourse. I mean it's new information about the subject. #4: this is a pretty clear case of "also" simply by looking the translation as well as #5's answer. So 「も」. This one is ok and doesn't require any further information. * Next one is #12 (I've included 11 for context): So #12 has three different blanks . What I'd like to put in place is some sort of protocol; a list of questions to remain methodical about picking the right particle. (1) Answer: は ① Is it a verb sentence? Yes. ② Is there a pronoun preceding the particle? No. ③ Is the sentence negative? Yes. So this could be a case of: When "wa" marks X, the speaker usually assumes that the hearer knows what X refers to. 今日 was identified in #11 and it's again repeated in #12. I'm going to go for this for my justification. (2) が I'd say: Indicates the subject of an intransitive verb. The intransitive verb being 「降りる」. (3) が ① Is it a verb sentence? No. It's an adjectivial sentence. I think it's a case of Indicates the subject of the sentence when new, as yet unknown information is being presented.