いつも・何時もitsumo[1]atamadaka (head-high)

1. adverbalways; all the time; at all times
   彼かれはいつも学校がっこうに遅おくれる。↗

   He is always late for school.
2. adverbneverwith neg. verb
   私は日曜日にちようびにはいつも家いえにいない。↗

   I'm never at home on Sundays.
3. no-adjectiveusual; regular; habitual; customary
   いつものところでいつもの人ひと達たちに会あった。↗

   I met the usual people at the usual place.

• Synonym常につねにWrittenWritten/formal prose. Covers every moment without exception, as in 「常に注意する」; more formal than 「いつも」 and stresses that there are no exceptions.
• Synonym絶えずたえずWrittenWritten/formal prose. Describes unbroken, continuous action, as in 「絶えず努力する」; it stresses nonstop continuity, while 「いつも」 stresses a habit repeated each time.
• SynonymいつでもNeutralNeutral. Means any time is fine, as in 「いつでも来て」; it stresses availability at any moment rather than habit, though it can also mean always.
• Synonym始終しじゅうWrittenWritten/formal prose. Covers a span from start to finish, as in 「始終笑っている」; it stresses the whole course of events, and can also mean generally always.
• SynonymしょっちゅうCasualColloquial. Means all too often, usually with a note of complaint, as in 「しょっちゅう遅刻する」; it stresses frequent repetition.
• Synonym年中ねんじゅうNeutralNeutral. Means all year round, as in 「年中無休」; it stresses the whole year through, and as an adverb it can also mean constantly, all the time.
• Synonym四六時中しろくじちゅうCasualColloquial. Means day and night, around the clock, as in 「四六時中考えている」; hyperbolic and stronger in tone than 「いつも」.
• Synonym常々つねづねWrittenWritten/formal prose. Means ordinarily, over time, mostly in 「常々思っていた」; it stresses long-held thoughts and is more solemn than 「いつも」.
• Synonym決まってきまってNeutralNeutral. Means invariably, whenever a given situation arises, as in 「雨の日は決まって頭痛がする」; it stresses no exceptions under that condition.
• RelatedとめどなくWrittenWritten/formal prose. Describes something pouring forth unstoppably, as in 「涙がとめどなく流れる」; it stresses being unable to stop, not a habit.
• Related明け暮れあけくれWrittenWritten/formal prose. Means devoting oneself to something from morning to night, as in 「練習に明け暮れる」; mostly used as a verb, and can also mean constantly.
• RelatedしきりにWrittenWritten/formal prose. Means again and again, as in 「しきりにうなずく」; it stresses repeated frequency, and can also mean eagerly or intensely.
• Related絶え間なくたえまなくWrittenWritten/formal prose. Describes something continuing without a gap, as in 「絶え間なく雨が降る」; it stresses unbroken continuity, while 「いつも」 stresses every time.
• Related年がら年中ねんがらねんじゅうCasualColloquial. Means all year long, stronger than 「年中」 and often with a complaining tone; in everyday speech 「いつも」 is enough.
• Related毎々まいまいWrittenWritten/formal prose. Means each and every time, mostly in polite set phrases like 「毎々お世話になります」; use 「いつも」 in daily life.
• Related常住坐臥じょうじゅうざがWrittenWritten/formal prose. A four-character idiom for every moment of daily life, sitting or sleeping; highly literary — say 「いつも」 or 「普段」 normally.
• Related年百年中ねんびゃくねんじゅうCasualColloquial. Means all year round, more exaggerated and folksier than 「年中」; people normally say 「年中」 or 「いつも」.
• Related間断なくかんだんなくWrittenWritten/formal prose. Describes something continuing without a break, as in 「間断なく続く」; it stresses no pause midway, not a habit.
• RelatedのべつまくなしCasualColloquial. Describes talking or going on endlessly, as in 「のべつ幕なしにしゃべる」; it stresses never stopping and often carries irritation.
• RelatedのべつCasualColloquial. Means on and on, one thing after another, usually with annoyance; it stresses ceaseless succession, while 「いつも」 leans toward habit.
• Related引きも切らずひきもきらずWrittenWritten/formal prose. Describes guests, calls and the like arriving one after another, as in 「客が引きも切らず訪れる」; it stresses a steady stream.
• Antonym決してけっしてWrittenWritten/formal prose. The opposite of 「いつも」: with a negative it means absolutely never, stressing the speaker's firm resolve or judgment.
• Antonym一度もいちどもNeutralThe opposite of 「いつも」: with a negative it means not even once, as in 「一度も行ったことがない」.

「いつも」 is the everyday default. For formal prose pick 「常に」; for unbroken continuity 「絶えず」 or 「絶え間なく」; for frequent repetition with a complaint 「しょっちゅう」; for any time is fine 「いつでも」; for what invariably happens in a situation 「決まって」. The year-round words 「年中」「年がら年中」 stress the whole year, the ceaseless words like 「のべつ」 stress nonstop action, and the antonyms 「一度も」「決して」 take negatives.

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

1. 普段ふだん。
2. 常つねに。しょっちゅう。