English can hides several questions that Thai usually keeps apart. Is the event practically possible? Has the person learned how? Does a formal description assert a capacity? Can someone cope with the present demand? The usual answers are event + ได้, learnable activity + เป็น, สามารถ + event (+ ได้), and event + ไหว respectively.
More than one sentence may be true of the same person. A driver can ขับรถเป็น “know how to drive” but วันนี้ขับรถไม่ได้ “cannot drive today,” or have both skill and opportunity but ขับต่อไม่ไหว “cannot manage driving farther.” The construction profiles the source of ability; it does not attach four interchangeable dictionary synonyms to a verb.
Compact comparison
| Intended question | Productive frame | What it profiles | Typical register |
|---|---|---|---|
| Is this event possible, available, permitted, or achievable? | event + ได้ | practical possibility | neutral |
| Does this person know how? | learnable activity + เป็น | acquired know-how | neutral |
| Does a person, device, or system have stated capacity? | สามารถ + event (+ ได้) | explicit general capacity | formal-neutral |
| Are present resources enough for this demand? | event + ไหว | strength, stamina, time, attention, or tolerance | neutral, especially conversational |
A four-step decision tree
1. Is the ability learned as a method or skill? Put เป็น after the complete activity. Swimming, driving, cooking, reading a map, and using equipment readily support this frame.
พี่สาวผมขับรถเป็นครับ
phi sao phom khap rot pen khrap
My older sister knows how to drive. (ordinary polite speech, male speaker; learned skill)
คุณอ่านโน้ตดนตรีเป็นไหมคะ
khun an not dontri pen mai kha
Do you know how to read music? (ordinary polite question, female speaker; acquired system knowledge)
2. Is one event possible because of circumstances, permission, an opportunity, or a functional ability? Put ได้ after the whole event. The source is often recovered from context.
เย็นนี้พี่สาวผมขับรถมารับได้ครับ
yen ni phi sao phom khap rot ma rap dai khrap
My older sister can drive over to pick us up this evening. (ordinary polite speech, male speaker; schedule and circumstances permit it)
ลูกค้าเปิดดูใบเสร็จในแอปได้ค่ะ
luk kha poet du bai set nai aep dai kha
Customers can view the receipt in the app. (polite service information, female voice; available function)
3. Are you explicitly describing a person's, device's, or system's general capacity in a policy, report, presentation, or technical explanation? Put สามารถ before the event; final ได้ commonly closes the frame.
อุปกรณ์นี้สามารถวัดอุณหภูมิได้ครับ
uppakon ni samat wat unhaphum dai khrap
This device can measure temperature. (formal-polite technical explanation, male voice)
4. Does a particular load test strength, stamina, attention, time, workload, or emotional tolerance? Put ไหว after that demand.
คืนนี้พี่สาวผมขับรถกลับไหวไหมคะ
khuen ni phi sao phom khap rot klap wai mai kha
Can my older sister manage driving back tonight? (ordinary polite question, female speaker; stamina under a demand)
The four-way ability overview develops the individual constructions; this page is for making the choice in real time.
One activity, four viewpoints
Hold อ่านเอกสารชุดนี้ “read this set of documents” constant and change only what the speaker is evaluating.
เจ้าหน้าที่ใหม่อ่านเอกสารภาษาไทยเป็นแล้วค่ะ
chaonathi mai an ekkasan phasa thai pen laeo kha
The new officer now knows how to read Thai documents. (formal-polite report, female voice; acquired literacy)
เจ้าหน้าที่ใหม่อ่านเอกสารชุดนี้ได้ค่ะ
chaonathi mai an ekkasan chut ni dai kha
The new officer can read this set of documents. (polite workplace report, female voice; practical ability or access)
เจ้าหน้าที่ใหม่สามารถอ่านเอกสารชุดนี้ได้ค่ะ
chaonathi mai samat an ekkasan chut ni dai kha
The new officer is capable of reading this set of documents. (formal workplace assessment, female voice)
เอกสารมีสองร้อยหน้า เจ้าหน้าที่ใหม่อ่านวันนี้ไม่ไหวค่ะ
ekkasan mi song roi na chaonathi mai an wan ni mai wai kha
The documents are two hundred pages long; the new officer can't manage reading them today. (polite workplace report, female voice; workload limit)
เป็น is impossible for a punctual event controlled only by availability: มาประชุมเป็น cannot mean “can attend this meeting.” ไหว needs an interpretable demand, so it is not a neutral replacement for learned know-how. สามารถ needs an event predicate, not a bare noun. ได้ is the broadest, but it does not automatically identify whether skill, permission, or circumstances create the possibility.
A potentially ambiguous ได้, resolved by a cue
The broad sentence เขายกกล่องนี้ได้ can report strength, permission, practical possibility, or successful performance. Add the cue that matters instead of replacing ได้ mechanically.
ตามกฎแล้ว เขายกกล่องนี้ออกไปได้ครับ
tam kot laeo khao yok klong ni ok pai dai khrap
Under the rules, he may carry this box out. (formal-polite statement, male voice; permission cue)
เมื่อวานเขายกกล่องนี้ขึ้นรถได้ครับ
muea wan khao yok klong ni khuen rot dai khrap
Yesterday he managed to lift this box onto the vehicle. (ordinary polite report, male speaker; successful performance cue)
เขาแข็งแรงพอ ยกกล่องนี้คนเดียวไหวครับ
khao khaengraeng pho yok klong ni khon diao wai khrap
He's strong enough to manage lifting this box alone. (ordinary polite report, male speaker; load and capacity made explicit)
The last sentence chooses ไหว because the point is not simply whether lifting is possible; it is whether one person's resources meet this particular load.
Negation and scope
Negation normally sits immediately before the potential element: event + ไม่ได้, activity + ไม่เป็น, ไม่สามารถ + event (+ ได้), and event + ไม่ไหว.
เขาใช้โปรแกรมนี้ไม่เป็นครับ แต่วันนี้เปิดโปรแกรมไม่ได้เพราะลืมรหัสผ่าน
khao chai prokraem ni mai pen khrap tae wan ni poet prokraem mai dai phro luem rahat phan
He doesn't know how to use this program, but today he can't open it because he forgot the password. (ordinary polite report, male speaker; skill versus current possibility)
Do not confuse postverbal ability ได้ with preverbal realized-event ได้. ได้คุย can mean “got to talk,” while คุยได้ means “can talk.” Likewise, ไม่ได้คุย usually denies that talking occurred, whereas คุยไม่ได้ denies its possibility.
Formal service dialogue
ผู้ใช้สามารถยืนยันตัวตนผ่านแอปได้ค่ะ
phu chai samat yuenyan tua ton phan aep dai kha
Users can verify their identity through the app. (formal service explanation, female officer)
ถ้าใช้แอปไม่เป็น ขอให้เจ้าหน้าที่ช่วยได้ไหมครับ
tha chai aep mai pen kho hai chaonathi chuai dai mai khrap
If I don't know how to use the app, may I ask an officer to help? (polite question, male customer)
ช่วยได้ค่ะ แต่ถ้ามีลูกค้าพร้อมกันหลายคน เจ้าหน้าที่คนเดียวอาจดูแลไม่ไหว
chuai dai kha tae tha mi luk kha phrom kan lai khon chaonathi khon diao at dulae mai wai
They can help, but if many customers arrive together, one officer may not be able to manage them. (formal-polite reply, female officer; practical possibility versus workload limit)
Here register favors สามารถ in the general policy. The customer's เป็น asks about learned procedure, and ไหว evaluates today's workload. Formal Thai does not erase these semantic contrasts.
Ordinary-polite dialogue
ว่ายน้ำเป็นไหมคะ
wai nam pen mai kha
Do you know how to swim? (ordinary polite question, female speaker; learned skill)
เป็นครับ แต่วันนี้ว่ายไกลไม่ไหว
pen khrap tae wan ni wai klai mai wai
Yes, but I can't manage swimming far today. (ordinary polite reply, male speaker; skill versus stamina)
งั้นว่ายในสระเล็กก็ได้ค่ะ
ngan wai nai sa lek ko dai kha
Then you can swim in the small pool. (ordinary polite suggestion, female speaker; available option)
ดีครับ แบบนั้นน่าจะว่ายไหว
di khrap baep nan na cha wai wai
Good. I should be able to manage that. (ordinary polite reply, male speaker; projected manageability)
The zero subjects are natural because the swimmers are established. Adding English pronouns to every line would make the dialogue unnecessarily heavy.
Common Mistakes
1. Putting the postverbal choices before the activity
❌ ฉันเป็นอ่านแผนที่ค่ะ
Incorrect learned-skill order; the complete activity must precede เป็น.
✅ ฉันใช้ตะเกียบเป็นค่ะ
chan chai takiap pen kha
I know how to use chopsticks. (ordinary polite speech, female speaker)
2. Using learned เป็น for one appointment
❌ วันศุกร์ผมเข้าประชุมเป็นครับ
Incorrect for availability on one date; attending this meeting is not learned know-how.
✅ วันศุกร์ผมเข้าประชุมได้ครับ
wan suk phom khao prachum dai khrap
I can attend the meeting on Friday. (ordinary polite speech, male speaker; schedule availability)
3. Using ไหว without a meaningful load
✅ วันนี้ลูกฉันอ่านหนังสือเล่มนี้ไม่ไหวค่ะ เนื้อหายากเกินไป
wan ni luk chan an nangsue lem ni mai wai kha nueaha yak koen pai
My child can't manage reading this book today; the content is too difficult. (female speaker; explicit demand makes ไหว appropriate)
✅ ลูกฉันอ่านหนังสือเป็นแล้วค่ะ
luk chan an nangsue pen laeo kha
My child knows how to read now. (ordinary polite speech, female speaker; learned ability)
4. Giving สามารถ a bare noun
❌ พนักงานสามารถภาษาเกาหลีครับ
Incorrect—สามารถ introduces an event predicate, not a bare language noun.
✅ พนักงานคนนี้สามารถสื่อสารภาษาเกาหลีได้ครับ
phanakngan khon ni samat suesan phasa kaoli dai khrap
This employee can communicate in Korean. (formal-polite assessment, male voice)
5. Assuming one choice expresses every source of “can”
English articles, infinitives, and modal order do not select the Thai form. Build the Thai event first, decide which relationship is being evaluated, and then place the construction in its Thai slot.
Key Takeaways
- Use event + ได้ for broad practical possibility, opportunity, permission, or achievement.
- Use learnable activity + เป็น for acquired know-how and event + ไหว for manageability under a present or projected load.
- Use สามารถ + event (+ ได้) for explicit capacity, especially in formal-neutral, policy, and technical language.
- More than one claim can be true: skill, opportunity, formal capacity, and stamina are independent dimensions.
- Keep objects and close complements inside the event; do not copy English modal or infinitive order.
Sources
- Shoichi Iwasaki and Preeya Ingkaphirom, A Reference Grammar of Thai, especially its chapter on Thai potential constructions.
- Pornthip Supanfai, Semantic Prosody in Thai, summarizes the three postclausal potential auxiliaries ได้, เป็น, and ไหว and their distinct semantic domains.
- “การวิเคราะห์คำว่า ‘ได้’ ตามแนวไวยากรณ์ศัพท์การก”, hosted by Kasetsart University, analyzes ได้ as expressing ability, possibility, and permission among its lexical-functional uses.
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Start learning Thai →Related Topics
- ได้, เป็น, สามารถ, and ไหวA2 — Choose among Thai constructions for practical possibility, learned skill, general capacity, and manageable limits.
- Ability and Opportunity with ได้A2 — Place ได้ after an event to express practical ability or opportunity, and use word order to separate can-do meaning from realized events.
- Learned Skill with เป็นA2 — Use an activity followed by เป็น to express learned know-how, and separate skill from present opportunity or stamina.
- Physical and Situational Capacity with ไหวA2 — Use ไหว after an event to judge whether physical, mental, or situational resources are enough for its demands.
- สามารถ in Neutral and Formal Ability StatementsA2 — Use สามารถ to state explicit capacity in professional, technical, and careful Thai, and contrast it with conversational postverbal ได้.
- ได้ as Get, Receive, Succeed, and Grammatical MarkerA2 — Use the position of ได้ to distinguish acquisition, event attainment, ability, permission, and success.