He/She clearly looked different from usual so I knew he/she hadn't just been drinking beer.
He/She clearly wasn't being his/her normal self so I knew it wasn't just beer.
He/She was staggering about and picking fights with everyone.
友人やパートナーが性格が非常に変わるまで飲むと大変ですよね。
明らかに ＝ clearly
いつもと様子が違う = looked different from usual ; wasn't being his/her normal self (文字通り＝「いつもの自分と違う」という表現です）
もうフラッフラ 異常に絡んでくるし＝＞
He/She was staggering about and picking fights with everyone.
quarrel; pick fights = 絡む
He was obviously acting differently than usual, so I knew it wasn’t just beer.
こんにちは！
ご質問ありがとうございます。
ご質問について、いくつか言い方が考えられますが、例えば、
He was obviously acting differently than usual, so I knew it wasn’t just beer.
とすると、「明らかにいつもと様子が違ったので、[ビール](https://eikaiwa.dmm.com/uknow/questions/47822/)じゃないのは分かった。」となります。
役に立ちそうな単語とフレーズ
obviously 明らかに
act differently than usual いつもと様子が違う
参考になれば幸いです。
アメリカ合衆国 
日本 
