That child is a headache.
子には 頭が 痛い。
Ano ko ni wa atama ga itai.
that (someone or something distant from both speaker and listener, or situation unfamiliar to both speaker and listener)
child; young (animal); young woman; young geisha; offshoot; interest; new shares; player who is not a dealer (in cards, mahjong, etc.); bird egg; -er (often of young women)
at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
head; hair (on one's head); mind; brains; intellect; leader; chief; boss; captain; top; tip; beginning; start; head; person; top structural component of a kanji
indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and
painful; sore; exceeding