太い

ふとい

fat, thick

i-adjective

Conjugation Table

Present

太い

Negative

太くない

Past

太かった

Past Negative

太くなかった

Te Form

太くて

Adverbial

太く

Conditional

太ければ

Presumptive

太いでしょう

Example Sentences

この木は太いです。

This tree is thick.

Kono ki wa futoi desu.

あのペンは太かったです。

That pen was thick.

Ano pen wa futokatta desu.

この線は太くないです。

This line is not thick.

Kono sen wa futokunai desu.

Grammar Notes & Usage Tips

•Conjugation Tip:** As an i-adjective, 太い (ふとい) follows the typical i-adjective pattern, so to say something is not fat or thick, change it to 太くない (ふとくない); for the past tense, use 太かった (ふとかった).

•Particle Usage:** When describing a noun, remember to place 太い before the noun, like 太い木 (ふといき) for "a thick tree," and use the particle が or は to mark the subject when making statements, like 木が太い (きがふとい) meaning "The tree is thick."

•Contextual Usage:** Be aware that 太い can describe both animate and inanimate objects, like 太い腕 (ふというで) for "thick arms," but it may convey a negative or impolite tone when referring to people, so use it carefully!

•Common Mistake:** Don't confuse 太い with 大きい (おおきい), which means "big" or "large." Remember, 太い specifically refers to the thickness or girth of an object, not its overall size.

•い-adjective: Conjugates by changing the い ending