Learn Hardcore Japanese: natu ni kazoku to issyo ni hanabi wo mimasu. - In summer, I watch fireworks with my family.

The particle に marks a point in time. Here, 夏に means “in summer.” Without に, 夏 would just be a noun with no clear grammatical role as a time expression.

Why is there no subject like “I” in the sentence?

Japanese often omits the subject when it’s clear from context. Since the speaker is talking about what they do, I is understood and doesn’t need to be stated.

What does と mean in 家族と?

The particle と indicates “with” when referring to companions. 家族と literally means “with (my) family.”

What exactly does 一緒に mean, and why is it followed by に again?

一緒 is a noun meaning “togetherness.” Adding に turns it into an adverb meaning “together” (describing how the action is done). So 一緒に = “together (with someone).”

Why is 花火 followed by を?

The particle を marks the direct object of the verb. 花火を見ます means “watch fireworks,” where 花火 is what you are watching.

Why does the verb 見ます come at the end of the sentence?

Japanese typically follows a Subject-Object-Verb (SOV) order, so the main verb naturally appears at the end of the clause.

Can we swap 一緒に and 家族と, for example say 一緒に家族と花火を見ます?

Short modifier phrases have some flexibility, so that sentence is still understandable. However, 家族と一緒に is more idiomatic when grouping “with family” and “together” as a single idea.

Can we omit the first に after 夏?

In casual conversation you might hear someone drop it, but in standard Japanese the time-marker に is usually required to signal that 夏 is acting as a temporal phrase.

Why is 花火 used without a counter or plural marker?

Japanese nouns don’t change form for singular/plural. When speaking of “fireworks” in general, you use 花火 with no plural marker. A counter (like 発) is only needed if you specify an exact number (e.g. 花火を三発見ます, “watch three fireworks”).