Look up this word
intensive

In a sentence
Počas leta absolvovala intenzívny kurz slovenčiny.
During the summer, she took an intensive Slovak course.
Intenzívny tréning pripravuje tím na finále.
Intensive training prepares the team for the final.
Po intenzívnom daždi sa rieka rýchlo rozvodnila.
After intense rain the river rose quickly.
Intenzívny tréning trval dva týždne.
The intensive training lasted two weeks.
Source
Slovak National Corpus (SNK) ↗English gloss from the frequency publish path. Hand-reviewed example sentences.
Full attribution on References.