Other forms: yesterdays
Yesterday is the day before today. It works as an adverb and as a noun without changing shape: I saw her yesterday, and yesterday was a long day.
It takes no preposition, and that is the error to guard against — not on yesterday, not in yesterday, just yesterday. The same is true of today and tomorrow, and the rule is easy to state and easy to forget. Combined forms are common and useful: yesterday morning, yesterday afternoon, yesterday evening — but last night, never yesterday night. And yesterday almost always takes the past simple, because the time is finished and named.
1adverbyesterdayOn the day before today.
“We arrived yesterday and leave on Friday.”
2noundayThe day before today.
“Yesterday was the worst of it.”
3nounrecentThe recent past, spoken of generally.
“The fashions of yesterday come round again.”
Too few real examples of this word to estimate which sense is commonest.
yesterday is a day.
Old English giestrandaeg is giestran, meaning yesterday, plus daeg, day. The first half is a genuinely ancient word — it shows up in Latin as heri and in German as gestern — and it never meant anything but the day before this one.
Middle English
yesterday
English, today
yesterday
Built from
From Middle English yesterday. From Middle English yesterday, yisterday, ȝesterdai, ȝisterdai, from Old English ġiestrandæġ, ġister dæġ, ġestor dæġ, ġeostran dæġ (“yesterday”), by surface analysis, en + yester + day. Cognate with Scots yisterday, yesterday (“yesterday”), stq jässendeeg, järsendeges (“yesterday”), West Frisian justerdei (“yesterday”), Dutch gisterdag (“yesterday”), dialectal German gestertag (“yesterday”), Swedish gårdag (“yesterday”), Gothic 𐌲𐌹𐍃𐍄𐍂𐌰𐌳𐌰𐌲𐌹𐍃 (“tomorrow”). Compare further Dutch gisteren (“yesterday”), German gestern (“yesterday”).
Etymology from Wiktionary, CC BY-SA