Questions & Answers about kono sake wa tsuyoi.
Because は is being used as a particle, specifically the topic particle.
When は is part of a word, it is usually pronounced ha.
But when it marks the topic of a sentence, it is pronounced wa.
So in this sentence:
- 酒 = the noun
- は = topic marker, pronounced wa
This is one of the first pronunciation exceptions Japanese learners memorize.
