“As you can see” is used to draw attention to something that is obvious or visible. For example, you might say “As you can see, the cat is sitting on the mat” or “As you can see, the results of the test are not good.”
“I can’t say” is used to express uncertainty or doubt. For example, you might say “I can’t say for sure when I’ll be finished with this project” or “I can’t say that I agree with your decision.”
“I can tell you that” is used to make a statement that is certain or factual. For example, you might say “I can tell you that the meeting will start at 10am” or “I can tell you that I’m not happy with the way things are going.”
“As you can imagine” is used to express something that is easy to understand or picture. For example, you might say “As you can imagine, I was very excited to get the job offer” or “As you can imagine, the traffic was terrible today.”
“I can say that” is used to make a statement that is true or accurate. For example, you might say “I can say that I’m very proud of my children” or “I can say that I’ve learned a lot from this experience.”
“I can assure you that” is used to express confidence or certainty. For example, you might say “I can assure you that I will do my best” or “I can assure you that your information is safe with me.”