In short

To say try doing something, add the auxiliary 보다 (literally to see) to the 아/어 form: 먹어 보세요 (meogeo boseyo, give it a taste). Put that same 보다 into the past and it flips to meaning have done / have experienced: 먹어 봤어요 (meogeo bwasseoyo, I’ve tried it). To spell out “have you ever…”, use the bound-noun frame -(으)ㄴ 적이 있다/없다: 제주도에 가 본 적이 있어요 (Jejudoe ga bon jeogi isseoyo, I’ve been to Jeju).

The rule

Step 1 - -아/어 보다: try doing it

Take the 아/어 form (lesson 10) and add 보다 as a separate word (it is an auxiliary, so it keeps its space): 먹다 -> 먹어 보다 (meogeo boda), 가다 -> 가 보다 (ga boda), 하다 -> 해 보다 (hae boda). Conjugate the 보다, not the main verb:

• Suggestion - try it: 입어 보세요 (ibeo boseyo, try it on).
• Volunteering - I’ll give it a go: 입어 볼게요 (ibeo bolgeyo, I’ll try it on).

One block: you cannot stack 보다 onto 보다 itself - 보다 already means “look”. *봐 보다 is wrong; to say “give it a look” use 한번 보세요 (hanbeon boseyo) or just 한번 봐요 (hanbeon bwayo). The pair negates as one block too, and the two negations split: the short 안/못 go in front of the main verb, never in front of 보다 - 못 가 봤어요 (mot ga bwasseoyo, I’ve never got to go), never *가 못 봤어요 - while the long -지 않다 / -지 못하다 attach to 보다 itself: 먹어 보지 않았어요 (meogeo boji anasseoyo), 먹어 보지 못했어요 (meogeo boji mothaesseoyo).

Step 2 - -아/어 봤어요: the past = an experience

Put 보다 in the past (보 + 았어요 -> 봤어요) and the meaning shifts from attempt to experience - I have done it (at least once): 한국 음식을 먹어 봤어요 (Hanguk eumsigeul meogeo bwasseoyo, I’ve tried Korean food). This is the everyday way to say “have you ever…”: 가 봤어요? (ga bwasseoyo?, have you been?).

Step 3 - -(으)ㄴ 적이 있다/없다: the explicit “have the experience of”

Attach the past modifier -(으)ㄴ to the verb, then the bound noun 적 (occasion) plus 있다 (there is) or 없다 (there isn’t). 적 is a separate word, so it always takes a space before it: 간 적이 있어요 (gan jeogi isseoyo, I have been), 먹은 적이 없어요 (meogeun jeogi eopseoyo, I’ve never eaten it). Negate with 없다, never *안 있다.

The two patterns stack: -아/어 보다 keeps its 보다, which is then modified as 본 -> -아/어 본 적이 있다. This is the most natural “have you ever tried…”: 제주도에 가 본 적이 있어요 (Jejudoe ga bon jeogi isseoyo), 번지점프를 해 본 적이 없어요 (beonjijeompeureul hae bon jeogi eopseoyo, I’ve never done bungee jumping).

Step 4 - Experience vs. plain event, and why recent things resist 적이 있다

갔어요 (gasseoyo) states a specific event - I went. 가 봤어요 / 간 적이 있어요 report an experience - I have (at some point) been. Because 적이 있다 packages the past as a notable, countable occasion, it clashes with events that are recent or routine: *어제 학교에 간 적이 있어요 is odd - going to school yesterday is an ordinary recent event, so just say 어제 학교에 갔어요. Reserve 적이 있다 for things worth calling an experience.

Step 5 - 적 vs 번

적 is a bound noun meaning the time or occasion of doing X; in this experience frame it takes the past modifier, -(으)ㄴ … 적이 있다. It also turns up after -(으)ㄹ meaning plain “when” - 어릴 적 (eoril jeok, “when I was little”) - but that is a time expression, not an experience claim. 번 (lesson 19) is a counter for counting how many times: 두 번 가 봤어요 (du beon ga bwasseoyo, I’ve been twice). Do not swap them: *간 번이 있어요 is wrong. Note also 한 번 (han beon, “one time”, spaced) vs 한번 (hanbeon, “give it a try, sometime”, one word) - the try-it 한번 sits happily in front of -아/어 보다.

Forms & patterns

-아/어 보다 - the 아/어 form plus the auxiliary 보다:

One verb, the whole range (먹다):

-(으)ㄴ 적이 있다 - the past modifier by last sound of the stem:

Event vs. experience:

Examples

Common mistakes

• 그 영화 한번 봐 보세요. (Geu yeonghwa hanbeon bwa boseyo.) -> 그 영화 한번 보세요. (Geu yeonghwa hanbeon boseyo.) - you cannot add try-보다 to 보다 itself; the plain verb already means take a look.
• 한국에 간적이 있어요. (Hanguge ganjeogi isseoyo.) -> 한국에 간 적이 있어요. (Hanguge gan jeogi isseoyo.) - 적 is a bound noun and needs a space before it; it is never glued to the modifier.
• 어제 학교에 간 적이 있어요. (Eoje hakgyoe gan jeogi isseoyo.) -> 어제 학교에 갔어요. (Eoje hakgyoe gasseoyo.) - a recent, routine event takes the plain past; 적이 있다 is for notable experiences, not yesterday’s commute.
• 한국에 간 번이 있어요. (Hanguge gan beoni isseoyo.) -> 한국에 간 적이 있어요. (Hanguge gan jeogi isseoyo.) - use 적 for experience; 번 only counts how many times (두 번, 세 번).
• 만나 본 적이 안 있어요. (Manna bon jeogi an isseoyo.) -> 만나 본 적이 없어요. (Manna bon jeogi eopseoyo.) - negate 있다 with its own antonym 없다, not with 안.

Tips

• 보다 = “see”, so the mnemonic writes itself: 먹어 보다 is eat and see -> try eating. The literal see meaning is exactly why you can’t stack it on 보다.
• Same auxiliary, tense flips the meaning. Present/imperative 보다 = attempt (먹어 보세요, try it); past 봤어요 = experience (먹어 봤어요, I’ve had it). Watch the tense to know which reading is meant.
• 적 wants a space, 번 wants a number. If you can put a count in front (two times), it’s 번; if you mean the occasion of ever doing it, it’s -(으)ㄴ 적이 있다. And 한 번도 (han beondo, not once) is that same 번 in its negative shape - it can only ever be finished with 없다, 안 or 못: 한 번도 가 본 적이 없어요 (han beondo ga bon jeogi eopseoyo), never *한 번도 가 봤어요.
• Recent or habitual? Drop 적이 있다. For last week, this morning, or everyday actions, plain 갔어요 / 먹었어요 is right; save 적이 있다 for real “life experience” claims.