常に|つねにtsuneni[1]atamadaka (head-high)

1. adverbalways; constantly; at all times; habitually
   常つねに疲労感ひろうかんがあります。↗

   I always have a tired feeling.

• Synonym常々つねづねNeutralRefers to what has long been the case, as in 「常々思っている」; mostly used for one's own thoughts, and leans toward written style.
• Synonym絶えずたえずNeutralMeans without interruption, as in 「絶えず努力する」; stresses unbroken continuity, while 「常に」 covers anything true at all times, whether a state or repeated events.
• SynonymいつもNeutralThe colloquial everyday word for always, as in 「いつも遅れる」; 「常に」 is the more written/formal choice.
• Synonym始終しじゅうNeutralMeans throughout, from start to finish, or constantly, as in 「始終しゃべっている」「始終お世話になっている」; stresses continuous repetition.
• SynonymしょっちゅうCasualColloquial, for happening often or at every turn, as in 「しょっちゅう遅刻する」; stresses frequency rather than constancy.
• SynonymとめどなくNeutralMeans endlessly, without stopping; mostly used of tears or talk, as in 「涙が止めどなく流れる」.
• Synonym年中ねんじゅうNeutralMeans all year round, as in 「年中無休」; also used adverbially to mean always.
• Synonym明け暮れあけくれWrittenMeans from morning to night; usually in the pattern 「～に明け暮れる」, spending one's days absorbed in something.
• Synonym四六時中しろくじちゅうNeutralMeans around the clock, at every hour of the day; often hyperbolic or negative in tone.
• Synonym絶え間なくたえまなくNeutralMeans without a moment's pause, as in 「絶え間なく雨が降る」; stresses unbroken continuity.
• SynonymいつでもNeutralMeans whenever, at any time, as in 「いつでも来て」; stresses that any time is fine.
• Synonym決まってきまってNeutralMeans invariably, whenever a given situation arises, as in 「雨の日は決まって頭痛がする」; regularity under a condition.
• Synonym年がら年中ねんがらねんじゅうCasualColloquial, for all year round or day in, day out, often with a complaining tone, as in 「年がら年中忙しい」.
• Synonym常住坐臥じょうじゅうざがWrittenA four-character idiom for every moment, sitting or lying, waking or sleeping; written style, not used in everyday life.
• Synonym年百年中ねんびゃくねんじゅうCasualColloquial, all year round; synonymous with 「年がら年中」 but used less often.
• Synonym日夕にっせきWrittenA written word for day and night, morning to evening, or dusk; almost unused today — say 「いつも」 or 「一日中」 instead.
• Synonym間断なくかんだんなくWrittenWritten style, meaning without interruption, as in 「間断なく続く」; more formal than 「絶えず」.
• SynonymのべつまくなしCasualColloquial and derogatory, for going on and on without a break, as in 「のべつ幕なしにしゃべる」.
• SynonymのべつCasualColloquial, nonstop; mostly seen in 「のべつ幕なし」, rarely used on its own.
• Synonym引きも切らずひきもきらずWrittenWritten style, for an unbroken stream, mainly of visitors or phone calls, as in 「客が引きも切らず訪れる」.
• Synonym常住じょうじゅうWrittenA written word; in Buddhism it means eternal and unchanging, or residing permanently in a place; rare as an adverb.
• RelatedしきりにNeutralMeans frequently, again and again, as in 「しきりに頷く」; stresses repetition, not constancy.
• Related末始終すえしじゅうWrittenAn old-fashioned word for forever or for life, looking ahead over one's whole lifetime; 「常に」 speaks of any time. Almost unused today.
• AntonymたまにNeutralAntonym: occasionally, once in a while, as in 「たまに外食する」 — the opposite of 「常に」's at all times.
• Antonym時々ときどきNeutralAntonym: sometimes, from time to time; more frequent than 「偶に」, and the opposite of 「常に」's at all times.
• Antonym稀にNeutralAntonym: rarely, seldom — even less frequent than 「偶に」 and leaning written; the opposite of 「常に」.

Use 「常に」 for something that holds at all times; in everyday speech say 「いつも」. For unbroken continuity choose 「絶えず」, for high frequency 「しょっちゅう」, and for 'any time you like' 「いつでも」. The opposites are 「時々」 and 「偶に」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. どんな時ときでも。いつも。