きのうの昼ごはんはどうでしたか。
- How was lunch yesterday?

きのうの昼ごはんはどうでしたか。 meaning: How was yesterday's lunch?

⚫︎ The sentence follows a typical Japanese sentence structure, which is Subject-Object-Verb, although the subject can often be omitted if it's clear from context. ⚫︎ This sentence does not explicitly state the subject, assuming it's understood. ⚫︎ きのう (yesterday) is a time adverb. ⚫︎ の (no) is a possessive particle, linking きのう and 昼ごはん. ⚫︎ 昼ごはん (lunch) is the subject of the sentence. ⚫︎ は (wa) is the topic marker particle, indicating the topic of the sentence is "yesterday's lunch". ⚫︎ どう (dou) is an adverb meaning "how". ⚫︎ でしたか (deshita ka) is the past tense polite form of the verb "to be" plus a question marker. The polite form is indicated by the use of です (desu) and ました (mashita). ⚫︎ か (ka) is the question particle, turning the statement into a question.

⚫︎ どう (dou) is an adjectival noun, also known as a na-adjective. ⚫︎ Adjectival nouns describe nouns and require the particle な (na) before the noun when modifying it directly (e.g., 元気な人 – a healthy person). In this sentence, どう modifies the verb でした (deshita). ⚫︎ でした (deshita) is the past tense polite form of the copula です (desu), which functions as the verb "to be" or "is/are/was/were" in this context. ⚫︎ The present tense polite form would be です (desu) and non-polite forms would be だ (da) and だった (datta) in past tense.

⚫︎ The structure どうでしたか (dou deshita ka) is a common fixed expression used to inquire about the state or condition of something in the past. ⚫︎ It directly translates to "How was...?" or "How did it go?". ⚫︎ It is often used to ask about experiences, events, meals, etc. ⚫︎ The structure can be modified to change the subject, for example, 今日のテストはどうでしたか - "How was today's test?"

⚫︎ The verb in this sentence is actually a form of the copula, which acts like a verb. ⚫︎ The base form is です (desu), meaning "is/are". ⚫︎ It is conjugated to でした (deshita) in the past tense. ⚫︎ でした (deshita) is the polite past tense form. The "polite" aspect comes from the use of です (desu). ⚫︎ The non-polite past tense form is だった (datta).

⚫︎ The particle は (wa) marks the topic of the sentence. It indicates what the speaker is talking about. In this case, it’s 昼ごはん (lunch). ⚫︎ は (wa) is often translated as "as for," or "speaking of," but its primary function is topic marking. ⚫︎ The particle か (ka) is a question marker. It turns a statement into a question. It is placed at the end of the sentence. ⚫︎ Without か (ka), the sentence would be a simple statement about the lunch. Adding か (ka) makes it a question.