Napetost mišića je niska.

to be

Breakdown of Napetost mišića je niska.

• nizak: low
• napetost mišića: muscle tension

Questions & Answers about Napetost mišića je niska.

Why is mišića in that form? Why not mišići or mišića?

Mišića is the genitive singular form of mišić (muscle).

In napetost mišića, Croatian is expressing the tension of the muscle / muscle tension. Very often, when English uses noun + noun combinations like muscle tension, Croatian uses:

• noun + genitive
• here: napetost + mišića

So:

• mišić = muscle
• mišića = of the muscle

About the alternatives:

• mišići = nominative plural, muscles
• mišića can also be genitive plural in some contexts, so the form itself may look the same, but here the phrase is normally understood as tension of the muscle or more generally muscle tension depending on context.

What case is napetost in?

Napetost is in the nominative singular.

It is the subject of the sentence:

• Napetost mišića = muscle tension
• je niska = is low

So the structure is basically:

• [subject] + [copula] + [predicate adjective]

That is why napetost stays in the nominative.