日本は島国だ。

日本は島国だ。

Japan is an island country.

日本(にっぽん)は島国(しまぐに)だ。

Nippon wa shimaguni da.

日本 (にほん、にっぽん)

Japan

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

島国 (しまぐに、とうごく)

island country (sometimes used as a metaphor for Japan)

だ (だ)

be; is; indicates past or completed action; indicates light imperative

Readings: ニチ、ジツ、ひ、 -び、 -か

Meanings: day, sun, Japan, counter for days

Readings: ホン、もと

Meanings: book, present, main, origin, true, real, counter for long cylindrical things

Readings: トウ、しま

Meaning: island

Readings: コク、くに

Meaning: country