Question

Read these sentences and choose the adjective: 1. Fast или Fastly runners win races. 2. They are really happily или happy

Answer 1

1. Fast (быстрый, в данном контексте быстрые)
2. Happy (счастливый, в данном контексте счастливы)

fastly и happily:

1) наречия (нам же нужны прилагательные)
2) не подходят по смыслу к данным предложениям (даже звучит кривовато )

Answer 2

In the sentences you provided:

1. The adjective is "fast," as it describes the runners.
2. The adjective is "happy," as it describes "They."