• Basic forms
• 濁る — become cloudy / base form
• 濁ります — becomes cloudy / masu form
• 濁った — became cloudy / ta form
• 濁って — becoming cloudy … / te form
• 濁らない — does not become cloudy / negative
• 濁れば — if (something) becomes cloudy / conditional
• Common expressions
• 水が濁る — the water becomes cloudy
• 声が濁る — one’s voice becomes unclear
• 空気が濁る — the atmosphere becomes tense
• More
• 濁っている — is cloudy / state

濁る（にごる） is a godan intransitive verb. It describes a state changing naturally, both physically (water, sound) and figuratively (mood, atmosphere).

• Basic forms
• 濁す — make cloudy; muddy / base form
• 濁します — makes cloudy / masu form
• 濁した — made cloudy / ta form
• 濁して — making cloudy … / te form
• 濁さない — do not make cloudy / negative
• 濁せば — if (one) makes something cloudy / conditional
• Common expressions
• 水を濁す — muddy the water
• 話を濁す — be vague; avoid a clear answer
• 真実を濁す — obscure the truth
• More
• 濁したくない — do not want to make (it) unclear / 〜たい form

濁す（にごす） is a godan transitive verb. It emphasizes intentional action — physically muddying something, or deliberately making a statement unclear.