Mia amiko preskaŭ forgesis la daton de la festo, sed li tamen alportas donacon.

My friend almost forgot the date of the party, but he still brings a present.

Breakdown of Mia amiko preskaŭ forgesis la daton de la festo, sed li tamen alportas donacon.

• la amiko: the friend
• li: he
• la: the
• sed: but

Questions & Answers about Mia amiko preskaŭ forgesis la daton de la festo, sed li tamen alportas donacon.

Why is it forgesis (past tense) but alportas (present tense)? Why aren’t they in the same tense?

Forgesis is past tense because the forgetting (or almost-forgetting) happened before the time of speaking.

Alportas is present tense, but here it has a near‑future / planned action meaning, similar to English “is bringing / will bring”. In Esperanto the present tense is often used for scheduled or clearly intended future actions.

You could change the meaning slightly by changing the tense:

• … sed li tamen alportos donacon. – more explicitly “but he will (in the future) bring a present anyway.”
• … sed li tamen alportis donacon. – “but he brought a present anyway.” → now the whole sentence is fully in the past.

The original mixes a past situation (he almost forgot) with a current plan (he is going to bring a gift anyway), which is natural in Esperanto.

Why do daton and donacon end in ‑n?