Plants' leaves do get brown and needs to be trimmed/plucked out, so it's actually okay, unless they all go brown, then that's the sign that it needs more water.
You can see the sign if your plant is thirsty, if the green leaves look thin and dry (like dry skin), then you haven't watered it enough. If it continues, it'll go brown and die. So long as there's green part and the green part is healthy looking green, then, it's growing fine.
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