The sentence "how I love you" is grammatically correct in English. However, it is not a complete sentence by itself as it lacks a subject and verb. It could be a fragment that is part of a longer sentence or a phrase expressing intense love or affection for someone.
The phrase "how I love you" can be considered correct English, although it may sound more poetic or old-fashioned. In standard English, it is more common to say "I love you" without the word "how." However, adding "how" can emphasize the intensity or depth of your love. It ultimately depends on the style or tone you want to convey.
