付(つ)いて行(い)けるto keep in pace with, to keep up with, to follow (someone's thought), to understand

授業(じゅぎょう)は難(むずか)しいですが、付(つ)いて行(い)けます。

The class is difficult, but I can keep up with it. {to keep in pace with, to keep up with, to follow (someone's thought), to understand}

疲(つか)れたので前(まえ)のランナーに付(つ)いて行(い)けません。

I'm tired, so I can't keep up with the previous runner. {to keep in pace with, to keep up with, to follow (someone's thought), to understand}

彼女(かのじょ)のクレイジーな考(かんが)えに付(つ)いて行(い)ける人(ひと)はいません。

There is no one who can keep up with her crazy ideas. {to keep in pace with, to keep up with, to follow (someone's thought), to understand}

もうリーダーの傲慢(ごうまん)さには付(つ)いて行(い)けないので、脱退(だったい)します。

I can no longer keep up with the leader's arrogance, so I will withdraw. {to keep in pace with, to keep up with, to follow (someone's thought), to understand}

家来(けらい)：「流石(さすが)にご主人(しゅじん)様(さま)のあの残忍(ざんにん)なやり方(かた)には付(つ)いて行(い)けないなぁ…。」

Servant: "As expected, I just can't keep up with that cruel method of our master..." {to keep in pace with, to keep up with, to follow (someone's thought), to understand}