ジョンは性格が陽気だ。

ジョンは性格が陽気だ。

John is cheerful by nature.

ジョンは性格(せいかく)が陽気(ようき)だ。

Jon wa seikaku ga yōki da.

は (は)

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

性格 (せいかく)

character; personality; disposition; nature

が (が)

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

陽気 (ようき)

cheerful; jovial; merry; lively; weather; season; spirit of yang

だ (だ)

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

Readings: セイ、ショウ、さが

Meanings: sex, gender, nature

Readings: カク、コウ、キャク、ゴウ

Meanings: status, rank, capacity, character, case (law, grammar)

Readings: ヨウ、ひ

Meanings: sunshine, yang principle, positive, male, heaven, daytime

Readings: キ、ケ、いき

Meanings: spirit, mind, air, atmosphere, mood