掲示板 Forums - How to differentiate these two words?

Context, lenght of the two words and rough "shape" of the sounds.

Japanese are more sensible to those than individual sounds and as you progress in japanese, you will be more sensible to that kind of things.
With renshuu, you can learn the "perfect pronounciation" of those words, so focus on that first. And try to learn that in words in context to as much as you can. Because it's that part that really help. The rythm is also very important.

Also, Japanese struggle a lot with individual words said out of context. I often asked question about individual words to some Japanese friends. But they often struggle to understand it. And it's not always my pronounciation. Often, it just that without context, individual words are hard to recognize/identify. But as soon as you provide some context, example sentences or the kanji, they understand it immediately.

So, don't worry too much about it. Later, you will be able to distinguish more easily かわいい and こわい when they are pronounced perfectly as you get used to japanese. And much later, you will rely more on context to distinguish words in fast spoken conversation with a lot of background noise like Japanese.

PS: fun fact (or not for learner) but even japanese struggle a lot with spoken japanese. Not on everything and not in the same way beginner in japanese do but still. They also rely a lot on subtitles (hence why subtitles are everywhere). I had a japanese friend told me that when they sometimes get lazy to listen when watching youtube and just rely on subtitles quite often. 聞き間違い (misshearing) clip on youtube are also quite common and fun to watch (also help to not get demotivated when struggling with spoken japanese ). So don't worry about it, you will get better with time.

Honestly, they don't really sound alike when spoken by a native or someone who is fluent. Beginners may make them sound similar due to inexperience. There are words that sound very similar or near identical, and then context usually clears out any doubt.

In English, it's the same. For example: borrow and borough.