{"id":8664,"date":"2026-08-24T00:09:41","date_gmt":"2026-08-24T00:09:41","guid":{"rendered":"https:\/\/18kenglish.com\/common-english-abbreviations\/"},"modified":"2026-08-24T00:09:41","modified_gmt":"2026-08-24T00:09:41","slug":"common-english-abbreviations","status":"publish","type":"post","link":"https:\/\/18kenglish.com\/id\/common-english-abbreviations\/","title":{"rendered":"\u82f1\u6587\u7e2e\u5beb\u5927\u5168 | 50 Common English Abbreviations You Must Know"},"content":{"rendered":"
\nQuick Answer:<\/strong> English abbreviations are shortened forms of words or phrases used in professional writing, digital messaging, and academic documents. The 50 most common ones \u2014 from ASAP<\/em> (as soon as possible) to PhD<\/em> (Doctor of Philosophy) \u2014 appear daily in business emails, Slack channels, and official forms. Mastering them means faster reading, cleaner writing, and stronger professional English. \u82f1\u6587\u7e2e\u5beb\u51fa\u73fe\u5728\u6bcf\u4e00\u5c01\u5546\u696d\u96fb\u5b50\u90f5\u4ef6\u548c\u5b78\u8853\u6587\u4ef6\u4e2d\uff0c\u662f\u53f0\u7063\u8077\u5834\u82f1\u6587\u7684\u5fc5\u5099\u6280\u80fd\u3002\n<\/div>\n

Taiwan professionals send thousands of English emails a year. The bottleneck isn’t vocabulary \u2014 most people know the individual words. The problem is the shorthand: that three-letter code sitting in a client message at 9 PM, or the initials on a contract nobody explains. According to research by Cambridge English, unfamiliar abbreviations are one of the top three communication barriers for non-native English speakers in Asian workplaces. This guide covers 50 of the most useful ones, grouped by where you’ll actually encounter them.<\/p>\n

\"common<\/p>\n

\u7e2e\u5beb vs. \u9996\u5b57\u6bcd\u7e2e\u7565\u8a5e [Abbreviations vs. Acronyms \u2014 Why the Difference Matters]<\/h2>\n

Most people treat “abbreviation” as a catch-all term, but there are actually three distinct types. An abbreviation<\/strong> is a shortened form of a single word \u2014 Dr.<\/em> for “Doctor” or Ave.<\/em> for “Avenue.” An acronym<\/strong> is built from initials and pronounced as a new word \u2014 NASA, AIDS, STEM. An initialism<\/strong> is also built from initials, but each letter is read separately \u2014 FBI (eff-bee-eye), BBC, KPI. The distinction matters when reading aloud: you say “the FBI” not “fib-ee.” For Taiwan learners, this is especially important in business presentations and meetings where spoken English is expected.<\/p>\n

\"business<\/p>\n

\u5546\u52d9\u82f1\u6587\u7e2e\u5beb [Business Email Abbreviations] \u2014 The 15 You Must Know<\/h2>\n

These appear in every professional inbox. If your work involves any English correspondence with international clients or colleagues, you will see all of these within your first week. Missing even one can lead to a missed deadline or a misunderstood instruction.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u7e2e\u5beb<\/th>\n\u5168\u540d<\/th>\n\u4e2d\u6587<\/th>\nExample<\/th>\n<\/tr>\n<\/thead>\n
ASAP<\/strong><\/td>\nas soon as possible<\/td>\n\u5118\u5feb<\/td>\n“Please send the report ASAP.”<\/td>\n<\/tr>\n
FYI<\/strong><\/td>\nfor your information<\/td>\n\u4f9b\u60a8\u53c3\u8003<\/td>\n“FYI, the meeting moved to 3 PM.”<\/td>\n<\/tr>\n
ETA<\/strong><\/td>\nestimated time of arrival<\/td>\n\u9810\u8a08\u62b5\u9054\/\u5b8c\u6210\u6642\u9593<\/td>\n“What’s the ETA on the proposal?”<\/td>\n<\/tr>\n
EOD<\/strong><\/td>\nend of day<\/td>\n\u4eca\u5929\u7d50\u675f\u524d<\/td>\n“I need this by EOD.”<\/td>\n<\/tr>\n
OOO<\/strong><\/td>\nout of office<\/td>\n\u4e0d\u5728\u8fa6\u516c\u5ba4<\/td>\n“Sarah is OOO until Monday.”<\/td>\n<\/tr>\n
CC<\/strong><\/td>\ncarbon copy<\/td>\n\u526f\u672c \/ \u6284\u9001<\/td>\n“CC me on that thread.”<\/td>\n<\/tr>\n
BCC<\/strong><\/td>\nblind carbon copy<\/td>\n\u5bc6\u4ef6\u526f\u672c<\/td>\n“BCC the legal team.”<\/td>\n<\/tr>\n
TBD<\/strong><\/td>\nto be determined<\/td>\n\u5f85\u5b9a<\/td>\n“Venue is TBD.”<\/td>\n<\/tr>\n
RSVP<\/strong><\/td>\nr\u00e9pondez s’il vous pla\u00eet<\/td>\n\u656c\u8acb\u56de\u8986<\/td>\n“RSVP by Friday.”<\/td>\n<\/tr>\n
NDA<\/strong><\/td>\nnon-disclosure agreement<\/td>\n\u4fdd\u5bc6\u5354\u8b70<\/td>\n“Sign the NDA before the demo.”<\/td>\n<\/tr>\n
FAQ<\/strong><\/td>\nfrequently asked questions<\/td>\n\u5e38\u898b\u554f\u984c<\/td>\n“Check the FAQ first.”<\/td>\n<\/tr>\n
KPI<\/strong><\/td>\nkey performance indicator<\/td>\n\u95dc\u9375\u7e3e\u6548\u6307\u6a19<\/td>\n“Our Q3 KPI targets are set.”<\/td>\n<\/tr>\n
ROI<\/strong><\/td>\nreturn on investment<\/td>\n\u6295\u8cc7\u5831\u916c\u7387<\/td>\n“What’s the ROI on this campaign?”<\/td>\n<\/tr>\n
HR<\/strong><\/td>\nhuman resources<\/td>\n\u4eba\u4e8b\u90e8<\/td>\n“Contact HR for the contract.”<\/td>\n<\/tr>\n
P&L<\/strong><\/td>\nprofit and loss<\/td>\n\u640d\u76ca\u8868<\/td>\n“Pull the Q2 P&L report.”<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

One usage note: ASAP can appear as “a.s.a.p.” in older British-style correspondence. Both are correct, but the no-period version now dominates in global digital communication. Also worth noting \u2014 EOB (end of business) is sometimes used interchangeably with EOD, but EOB implies the formal close of business hours, while EOD is more flexible and sometimes means before midnight.<\/p>\n

\"professional<\/p>\n

\u6b63\u5f0f\u7a31\u8b02\u7e2e\u5beb [Formal Titles and Address Abbreviations]<\/h2>\n

These appear in letters, on envelopes, and in formal documents. Getting them wrong \u2014 using “Mr.” for a woman, for instance \u2014 creates an awkward first impression that can stick through an entire business relationship.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u7e2e\u5beb<\/th>\n\u5168\u540d<\/th>\n\u4e2d\u6587<\/th>\nNote<\/th>\n<\/tr>\n<\/thead>\n
Mr.<\/strong><\/td>\nMister<\/td>\n\u5148\u751f<\/td>\nFor men (married or single)<\/td>\n<\/tr>\n
Mrs.<\/strong><\/td>\nMissus<\/td>\n\u592a\u592a \/ \u592b\u4eba<\/td>\nFor married women only<\/td>\n<\/tr>\n
Ms.<\/strong><\/td>\n(no full form)<\/td>\n\u5973\u58eb<\/td>\nSafe for all women; doesn’t reveal marital status<\/td>\n<\/tr>\n
Dr.<\/strong><\/td>\nDoctor<\/td>\n\u91ab\u751f \/ \u535a\u58eb<\/td>\nUsed for both medical doctors and PhD holders<\/td>\n<\/tr>\n
Prof.<\/strong><\/td>\nProfessor<\/td>\n\u6559\u6388<\/td>\nUniversity teaching position<\/td>\n<\/tr>\n
Jr.<\/strong><\/td>\nJunior<\/td>\n\u5c0f \/ \u4e8c\u4e16<\/td>\nSon with same name as father: “Martin Luther King Jr.”<\/td>\n<\/tr>\n
Sr.<\/strong><\/td>\nSenior<\/td>\n\u8001 \/ \u4e00\u4e16<\/td>\nFather when son has same name<\/td>\n<\/tr>\n
St.<\/strong><\/td>\nStreet \/ Saint<\/td>\n\u8857\u9053 \/ \u8056\u4eba<\/td>\nContext tells you which: “Main St.” vs. “St. Patrick”<\/td>\n<\/tr>\n
Ave.<\/strong><\/td>\nAvenue<\/td>\n\u5927\u9053<\/td>\n“5th Ave.” in New York<\/td>\n<\/tr>\n
Blvd.<\/strong><\/td>\nBoulevard<\/td>\n\u6797\u852d\u5927\u9053<\/td>\n“Hollywood Blvd.”<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

A quick tip for Taiwan professionals: in English emails, if you’re unsure of someone’s gender, use “Ms.” for women and “Mr.” for men \u2014 or better, just use their first name and skip the title entirely. Most native English speakers in business settings now default to first names after the opening exchange. Forcing a formal title when the other party is using first names can actually read as stiff or distant.<\/p>\n

\"professional<\/p>\n

\u62c9\u4e01\u6587\u7e2e\u5beb [Latin Abbreviations That Never Left English]<\/h2>\n

English borrowed heavily from Latin, and several Latin abbreviations became so embedded in formal writing that they never left. They appear in academic papers, legal contracts, and everyday explanations \u2014 and they trip up advanced learners precisely because the full forms are in a foreign language.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
\u7e2e\u5beb<\/th>\n\u62c9\u4e01\u5168\u540d<\/th>\n\u82f1\u6587\u542b\u7fa9<\/th>\n\u4e2d\u6587<\/th>\n<\/tr>\n<\/thead>\n
i.e.<\/strong><\/td>\nid est<\/td>\nthat is (restatement)<\/td>\n\u4e5f\u5c31\u662f\u8aaa\uff08\u7528\u4f86\u89e3\u91cb\uff09<\/td>\n<\/tr>\n
e.g.<\/strong><\/td>\nexempli gratia<\/td>\nfor example<\/td>\n\u4f8b\u5982\uff08\u5f8c\u63a5\u4f8b\u5b50\uff09<\/td>\n<\/tr>\n
etc.<\/strong><\/td>\net cetera<\/td>\nand so on<\/td>\n\u7b49\u7b49\uff08\u5217\u8209\u672a\u5b8c\uff09<\/td>\n<\/tr>\n
vs.<\/strong><\/td>\nversus<\/td>\nagainst \/ compared to<\/td>\n\u5c0d\u6bd4 \/ \u76f8\u5c0d\u65bc<\/td>\n<\/tr>\n
N\/A<\/strong><\/td>\nnon applicatur<\/td>\nnot applicable<\/td>\n\u4e0d\u9069\u7528<\/td>\n<\/tr>\n
P.S.<\/strong><\/td>\npost scriptum<\/td>\nafter writing<\/td>\n\u9644\u8a00\uff08\u4fe1\u672b\u88dc\u5145\uff09<\/td>\n<\/tr>\n
a.k.a.<\/strong><\/td>\n\u2014<\/td>\nalso known as<\/td>\n\u53c8\u540d \/ \u5225\u540d<\/td>\n<\/tr>\n
approx.<\/strong><\/td>\napproximatus<\/td>\napproximately<\/td>\n\u5927\u7d04<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The most commonly confused pair: i.e.<\/em> versus e.g.<\/em> A reliable trick \u2014 “i.e.” signals a restatement or clarification of what you just said, while “e.g.” introduces examples. So: “I only drink one type of liquid, i.e., water” (complete restatement). “I drink various liquids, e.g., water, coffee, tea” (partial list). After e.g.<\/em>, a comma follows in American English. After etc.<\/em>, no “and” is needed \u2014 et cetera<\/em> already contains the “and.”<\/p>\n

\u6578\u4f4d\u901a\u8a0a\u7e2e\u5beb [Digital and Text Message Abbreviations]<\/h2>\n

These spread from English-speaking teenagers in the early 2000s and now appear in Slack channels, LINE group chats with international teams, and even semi-formal Zoom conversations. Some are universal; others are generational. The ones below are safe to use in any English-speaking digital context in 2026.<\/p>\n

\"text<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u7e2e\u5beb<\/th>\n\u5168\u540d<\/th>\n\u4e2d\u6587<\/th>\n\u4f7f\u7528\u6642\u6a5f<\/th>\n<\/tr>\n<\/thead>\n
LOL<\/strong><\/td>\nlaughing out loud<\/td>\n\u5927\u7b11<\/td>\nVery casual; shows something is funny<\/td>\n<\/tr>\n
BTW<\/strong><\/td>\nby the way<\/td>\n\u9806\u5e36\u4e00\u63d0<\/td>\nCasual to semi-casual; introducing a side point<\/td>\n<\/tr>\n
IMO<\/strong><\/td>\nin my opinion<\/td>\n\u4f9d\u6211\u4e4b\u898b<\/td>\nCasual opinion sharing<\/td>\n<\/tr>\n
IMHO<\/strong><\/td>\nin my humble opinion<\/td>\n\u4e0d\u624d\u8a8d\u70ba<\/td>\nSame as IMO, slightly softer or ironic<\/td>\n<\/tr>\n
TBH<\/strong><\/td>\nto be honest<\/td>\n\u8aaa\u5be6\u8a71<\/td>\nUsed before a frank or blunt remark<\/td>\n<\/tr>\n
BRB<\/strong><\/td>\nbe right back<\/td>\n\u99ac\u4e0a\u56de\u4f86<\/td>\nStepping away briefly from a live chat<\/td>\n<\/tr>\n
AFK<\/strong><\/td>\naway from keyboard<\/td>\n\u96e2\u958b\u96fb\u8166<\/td>\nLonger absence than BRB; common in gaming and Slack<\/td>\n<\/tr>\n
DM<\/strong><\/td>\ndirect message<\/td>\n\u79c1\u8a0a<\/td>\n“DM me the details.”<\/td>\n<\/tr>\n
FOMO<\/strong><\/td>\nfear of missing out<\/td>\n\u932f\u5931\u6050\u61fc<\/td>\nWidely used in marketing and social media<\/td>\n<\/tr>\n
TL;DR<\/strong><\/td>\ntoo long; didn’t read<\/td>\n\u592a\u9577\u4e0d\u770b<\/td>\nPlaced before a summary of a long post<\/td>\n<\/tr>\n
WFH<\/strong><\/td>\nwork from home<\/td>\n\u5728\u5bb6\u5de5\u4f5c<\/td>\nNow standard in business and HR contexts<\/td>\n<\/tr>\n
IRL<\/strong><\/td>\nin real life<\/td>\n\u73fe\u5be6\u4e2d<\/td>\n“Let’s meet IRL next month.”<\/td>\n<\/tr>\n
AFAIK<\/strong><\/td>\nas far as I know<\/td>\n\u5c31\u6211\u6240\u77e5<\/td>\nCasual hedge on information accuracy<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

TL;DR has crossed into professional writing. You’ll see it in Substack newsletters, internal memos, and academic Reddit threads. It signals that the writer is giving you a summary upfront \u2014 a courtesy, not laziness. WFH is now as likely to appear in a formal HR policy as in a text message. If you’re writing to an international team and mention that you’re WFH today, nobody will misunderstand.<\/p>\n

\u5b78\u8853\u82f1\u6587\u7e2e\u5beb [Academic and Qualification Abbreviations]<\/h2>\n

\"university<\/p>\n

Taiwan students applying to graduate programs abroad encounter these on application forms, in reference letters, and on degree certificates. Mislabeling your own degree \u2014 writing “MS” when your certificate says “MA” \u2014 looks careless on an application and can raise questions with admissions officers.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u7e2e\u5beb<\/th>\n\u5168\u540d<\/th>\n\u4e2d\u6587<\/th>\n<\/tr>\n<\/thead>\n
PhD<\/strong><\/td>\nDoctor of Philosophy<\/td>\n\u54f2\u5b78\u535a\u58eb\uff08\u535a\u58eb\u5b78\u4f4d\uff09<\/td>\n<\/tr>\n
MA<\/strong><\/td>\nMaster of Arts<\/td>\n\u6587\u5b78\u78a9\u58eb<\/td>\n<\/tr>\n
MS \/ MSc<\/strong><\/td>\nMaster of Science<\/td>\n\u7406\u5b78\u78a9\u58eb<\/td>\n<\/tr>\n
MBA<\/strong><\/td>\nMaster of Business Administration<\/td>\n\u5de5\u5546\u7ba1\u7406\u78a9\u58eb<\/td>\n<\/tr>\n
BA<\/strong><\/td>\nBachelor of Arts<\/td>\n\u6587\u5b78\u5b78\u58eb<\/td>\n<\/tr>\n
BS \/ BSc<\/strong><\/td>\nBachelor of Science<\/td>\n\u7406\u5b78\u5b78\u58eb<\/td>\n<\/tr>\n
GPA<\/strong><\/td>\ngrade point average<\/td>\n\u6210\u7e3e\u5e73\u5747\u7e3e\u9ede<\/td>\n<\/tr>\n
IQ<\/strong><\/td>\nintelligence quotient<\/td>\n\u667a\u5546<\/td>\n<\/tr>\n
STEM<\/strong><\/td>\nScience, Technology, Engineering, Mathematics<\/td>\n\u7406\u5de5\u79d1<\/td>\n<\/tr>\n
GRE<\/strong><\/td>\nGraduate Record Examination<\/td>\n\u7f8e\u570b\u7814\u7a76\u751f\u5165\u5b78\u8003\u8a66<\/td>\n<\/tr>\n
IELTS<\/strong><\/td>\nInternational English Language Testing System<\/td>\n\u96c5\u601d\u82f1\u8a9e\u8003\u8a66<\/td>\n<\/tr>\n
TOEFL<\/strong><\/td>\nTest of English as a Foreign Language<\/td>\n\u6258\u798f\u82f1\u8a9e\u8003\u8a66<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u82f1\u6587\u7e2e\u5beb\u4f7f\u7528\u539f\u5247 [4 Rules for Using Abbreviations Correctly]<\/h2>\n

\"English<\/p>\n

Knowing what an abbreviation means is half the skill. Knowing when to use it is the other half. Four situations catch Taiwan learners off-guard:<\/p>\n

The first-mention rule.<\/strong> In any formal document, write the full term the first time, then put the abbreviation in parentheses. After that, the abbreviation alone is fine. “We reviewed the Service Level Agreement (SLA) before signing. The SLA requires a 99.9% uptime guarantee.” \u2014 this pattern is standard in business proposals, legal documents, and academic papers.<\/p>\n

Register mismatch.<\/strong> LOL and TBH belong in chat windows, not client emails. ASAP is fine in emails. FYI crosses into formal writing occasionally. When in doubt, spell it out \u2014 it never reads as unprofessional.<\/p>\n

International audiences.<\/strong> Not every abbreviation travels equally. P&L and KPI are understood globally. WFH spread fast enough to be safe worldwide. But sending AFAIK or BRB in an email to a client in Japan or Germany might read as sloppy. Know your audience.<\/p>\n

Periods and capitalization.<\/strong> American English drops most periods in abbreviations \u2014 Mr, Dr, US, UK. British English keeps them \u2014 Mr., Dr., U.S., U.K. Since most Taiwan companies deal with American clients, the no-period style is usually safer. Latin abbreviations (i.e., e.g., etc.) keep their periods in both styles. Don’t mix conventions in the same document.<\/p>\n

\"office<\/p>\n

\u7df4\u7fd2\u8207\u5ef6\u4f38\u5b78\u7fd2 [Practice and Next Steps]<\/h2>\n

The 50 abbreviations here cover the four environments where Taiwan learners encounter English shorthand most: business emails, formal documents, digital chat, and academic settings. The business category is the most urgent \u2014 ASAP, FYI, EOD, TBD, CC, and OOO will appear in your inbox in the first week of any English-facing job.<\/p>\n

The best way to retain these isn’t a flashcard deck \u2014 it’s real exposure. Find an English podcast, newsletter, or Slack community in your field and read it weekly. You’ll see these abbreviations in context, which is how they actually stick. For related vocabulary, check out the complete guide to English expressions in context<\/a> and the English vocabulary by topic series<\/a> for travel, technology, and health terms. For the phrasal verbs that pair naturally with these abbreviations in business writing, the phrasal verbs with GET guide<\/a> covers the most common office English patterns.<\/p>\n

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