usredotočivati

1. Croat. (with se, na + acc.) to concentrate; to focus
   Teško se usredotočujem kad je buka. — I find it hard to concentrate when it's noisy.
   Usredotočujemo se na najvažnije zadatke. — We focus on the most important tasks.
2. Croat. (na + acc.) to concentrate; to focus
   Vlada usredotočuje sredstva na obrazovanje. — The government is focusing funds on education.

In Serbia the words are usredsređivati (se) or koncentrisati (se).