I don't want to disguise that from you
I don't want to exaggerate
I don't want to seem critical
I doubt the truth of that saying
I endorse it, every word
I entirely approve of your plan
I fancy it's just that
I fear I cannot help you
I fear that's too technical for me
I feel a certain apprehension
I feel an unwonted sense of gaiety [unwonted = unusual]
I feel it my duty to be frank with you
I feel myself scarcely competent to judge
I feel very grateful to you for your kind offer
I find it absorbing
I find it rather monotonous
I find this agreeable mental exhilaration
I frankly confess that
I generally trust my first impressions
I give my word gladly
I give you my most sacred word of honor
I had better begin at the beginning
I had no intention of being offensive
I hadn't thought of it in that light
I hardly think that could be so
I have a hundred reasons for thinking so
I have a peculiar affection for it
I have an immense faith in him
I have been constrained by circumstances
I have been decidedly impressed
I have been longing to see more of you
I have been puzzling over a dilemma
I have every reason to think so
I have given you the best proof of it
I have gone back to my first impressions
I have known striking instances of the kind
I have never heard it put so well
I have no delusions on that score
I have not succeeded in convincing myself of that
I have not the influence you think
I have not the least doubt of it
I haven't the remotest idea
I have often a difficulty in deciding
I have often marveled at your courage
I have quite changed my opinion about that
I have something of great importance to say to you
I have sometimes vaguely felt it
I have the strongest possible prejudice against it
I heartily congratulate you
I hope it will not seem unreasonable to you