Translation:The movie is short.
Pronunciation of consonant clusters in the syllable coda position:
• 앉다→[안따] (to sit)
• 괜찮다→[괜찬타] (to be okay)
• 읽다→[익따] (to read)
• 짧다→[짤따] (to be short)
• 읊다→[읍따] (to recite)
• 싫다→[실타] (to dislike)
• 값→[갑] (price)
When followed by a vowel, both consonants surface, unless the second consonant is ㅎ in which case it is ignored. When ㅎ is the second letter, the following consonant is aspirated if possible (above example with 싫다→[실타]).
When followed by ㅎ, the second consonant surfaces as an aspirate.
Keep in mind that other rules apply after consonant cluster reduction is applied!
In case of pronunciation, does the intonation you put into a word matter? Cause, I was pronouncing it just as you explained and as I listened to the example 짧습니다 (짤습니다) but it told me I was wrong the whole time, until I literally said it with the same intonation as the example. Does it matter to that point? (Sorry for the bad English, I speak spanish)
For syllables where the 받침 is -ㄹㅂ, the ㄹ is pronounced and the ㅂ is silent.
- 짧습니다 → [짤씀니다]
- 짧아요 → [짤바요]
★ Corrected typo 2017-09-19; see comment by Ash-Fred: https://www.duolingo.com/comment/24450613$comment_id=24511035
In actuality, it's even more complicated. This particular cluster has 3 different possible morphologies:
- Action verbs reduce |ㄼ| to /ㅂ/.
- ⟨밟다⟩ is [밥따] and ⟨밟으니⟩ is [발브니]
- Descriptive verbs reduce |ㄼ| to /ㄹ/.
- ⟨넓다⟩ is [널따] and ⟨넓으니⟩ is [널브니]
- ⟨섧다⟩ also reduces |ㄼ| to /ㄹ/. But the ⟨ㅂ⟩ represents a weak ㅂ, which becomes /ㅜ/ before a vowel.
- ⟨섧다⟩ is [설따] but ⟨설우니⟩ is [서루니]
Descriptive verbs (좋다 to be good) and action verbs (가다 to go) use the same endings for 3 of the 4 most common speech levels: casual (-아/어), polite (-아/어요), and formal (ㅂ니다). They use slightly different endings for the plain/diary/written form and in other instances as well (e.g. modifier forms).
HOWEVER, not all adjectives are descriptive verbs. Verbs like 싶다 and 슬프다 are descriptive verbs but 싶어하다 and 슬퍼하다 are actions verbs. The action verbs can take objects and be used in imperatives and describe the emotions/thoughts of 3rd person subjects, while their descriptive counterparts can't (or shouldn't).
[Not all adjectives ending in -하다 are action verbs. If the verb came from a descriptive verb (좋다 to 좋아하다) it's an action verb. But if it came from a noun (행복 to 행복하다) it's descriptive.]