You can tell someone what you’re thinking, and convey that in a way that you believe is correct. But that’s only a very small part of what it means to communicate something.
Communication happens through the words you choose to say, the words you leave unsaid, the way your words are shared, and the language your body is presenting (if you’re in person). You also communicate through the way you approach a project, how you talk to your team members, what you choose to share publicly and what is only said behind closed doors.
You also communicate through built up trust over an extended period of time. If a close friend tells you something that’s hard to hear, but says it in just the right way, it might have an impact. If a coworker with a bone to pick says something in a spiteful manner (even if they’re right), well you’re unlikely to take much notice.
All of this, and more, is important to keep in mind when trying to share your thoughts. It’s the responsibility of the sharer to convey what they mean to share.