to utter words in order to convey information, an opinion, a feeling or intention

कहना

English Usage: She didn't say anything during the meeting.

Hindi Usage: उसने बैठक के दौरान कुछ नहीं कहा।

to indicate the moment at which an action should start or stop

बताना कि कब

English Usage: Just say when, and I'll help you with your project.

Hindi Usage: बस बताना कि कब, और मैं आपकी परियोजना में मदद करूंगा।

the right or authority to express an opinion

राय

English Usage: Everyone should have a say in the decision-making process.

Hindi Usage: सभी को निर्णय लेने की प्रक्रिया में अपनी राय रखनी चाहिए।