I guess that's

I guess that's just who you are.

Je suppose que c’est simplement comme ça que tu es.

— A Silent Voice: The Movie (2016)

I guess that's not such a big secret.

Je suppose que ce n’est pas un si grand secret.

I guess that's possible.

Je suppose que c’est possible.

I guess that's what she's thinking.

Je suppose que c’est ce qu’elle pense.

— Broker (2022)

I guess that's impossible.

Je suppose que c’est impossible.

I guess that's what I'll do.

Je suppose que c’est ce que je vais faire.

I guess that's all I need.

Je suppose que c’est tout ce dont j’ai besoin.

I guess that's why I love you.

Je suppose que c’est pour ça que je t’aime.