Translation guide
The English word "stalk" has two main meanings: the stem of a plant, and the act of following or harassing someone. These meanings are completely separate in Japanese.
The main stem of a plant, leaf, flower, or fruit.
General word for the stalk or stem of a plant.
セロリの茎を刻んでください。
Please chop the celery stalks.
Often used for the central stalk of a leaf or feather, or the axis of a plant.
To follow someone persistently and obsessively, often in a threatening way.
The most common way to say "to stalk" someone, using the loanword "stalker" as a noun and adding "行為をする" (to commit the act).
彼は元カノにストーカー行為をして逮捕された。
He was arrested for stalking his ex-girlfriend.
The plant meaning and the following meaning are completely unrelated in Japanese. Using 茎 (kuki) to mean "stalk someone" would be nonsensical.
つきまとう is a broader term for following someone around persistently, which can include stalking but also less severe behavior. ストーカー行為をする specifically refers to the crime or act of stalking, often with legal implications.
The leaf stalk is broken.
A native Japanese verb meaning to follow someone around persistently, often with a negative connotation. It can be used for stalking or just being a nuisance.
知らない男が私をつきまとっている。
A strange man is stalking me.
The verb form of "stalking," used as a suru-verb. Less common than the noun phrase, but understood.
彼女はSNSで彼をストーキングしている。
She is stalking him on social media.
Means "to track" or "to pursue." It can be used for stalking in a more literal sense of following someone's movements, but it lacks the obsessive/harassing nuance unless context is added.
探偵は浮気の証拠をつかむために彼を追跡した。
The detective stalked him to get evidence of the affair.