Learn Croatian: Poslat ću pedeset poruka. - I will send fifty messages.

Pedeset is a combination of pet (five) and deset (ten). Notice that the 't' in pet changes to a 'd' to make it easier to pronounce. This pattern is used for most of the tens, like šezdeset (sixty) and sedamdeset (seventy).

Why is the word for messages poruka instead of the regular plural poruke?

In Croatian, numbers from five upwards (including pedeset) require the noun that follows them to be in the genitive plural case. For the feminine noun poruka (message), the genitive plural form happens to be spelled exactly the same as the singular poruka, although it is pronounced with a longer vowel at the end in spoken Croatian.

Why is the verb spelled poslat instead of its full dictionary form poslati?

This is a spelling rule for the future tense. When an infinitive verb ends in '-ti' and comes directly before the future helper verb (like ću), the final 'i' is dropped. Therefore, poslati ću becomes poslat ću.

Where is the word for 'I' in this sentence?