Learn Turkish: Her ay yatırım için para biriktireceğim. - Every month I will save money for an investment.

When you add the first-person suffix -im ("I") to the future tense -ecek, the k ends up between two vowels (e and i). In Turkish, a k caught between vowels almost always softens into a ğ. So, biriktirecek-im mutates and becomes biriktireceğim.

I thought the verb for "to save" was kurtarmak. Why are we using biriktirmek?

Kurtarmak means "to save" in the sense of rescuing someone or something from danger. When you want to say "save" in the sense of saving up money, collecting, or accumulating something over time, you must use biriktirmek.

Why does için come after yatırım?

In English, "for" is a preposition, so it comes before the noun ("for an investment"). In Turkish, için (for) is a postposition. This means it must always come right after the word it attaches to, creating yatırım için.

Should para be plural if I plan to save a lot of money every month?

No, you don't need to make it plural. Just like in English, "money" is treated as a general, uncountable concept in this context. Saying para biriktireceğim is the perfectly natural way to say "I will save money."