• Basic forms
• 寝る — sleep; go to bed / base form
• 寝ます — sleeps; goes to bed / masu form
• 寝た — slept; went to bed / ta form
• 寝て — sleeping … / te form
• 寝ない — do not sleep / negative
• 寝れば — if (one) sleeps / conditional
• Common expressions
• 早く寝る — go to bed early
• ぐっすり寝る — sleep soundly
• 横になって寝る — lie down and sleep
• More
• 寝ている — is sleeping; is in bed / state

寝る（ねる） is an ichidan intransitive verb. It refers to sleeping or going to bed.

• Basic forms
• 寝かす — put to sleep; lay down / base form
• 寝かします — puts to sleep / masu form
• 寝かした — put to sleep / ta form
• 寝かして — putting to sleep … / te form
• 寝かさない — do not put to sleep / negative
• 寝かせば — if (one) puts (someone) to sleep / conditional
• Common expressions
• 子どもを寝かす — put a child to sleep
• 赤ちゃんを寝かす — lay a baby down
• 布団に寝かす — lay someone on a futon
• More
• 寝かせる — causative form
• 寝かしている — is putting (someone) to sleep / state

寝かす（ねかす） is a godan transitive verb. It means to cause someone to sleep or to lay someone down.