Luotan tähän kurssiin.

I trust this course.

Breakdown of Luotan tähän kurssiin.

• minä: I
• tämä: this
• kurssi: the course
• luottaa: to trust
• -iin: to/into

Questions & Answers about Luotan tähän kurssiin.

Why does luotan end in -n?

Because luotan is the 1st person singular present tense form of the verb luottaa (to trust).

• minä luotan = I trust
• sinä luotat = you (sg) trust
• hän luottaa = he/she trusts
  So the -n is the normal personal ending for I in the present tense.

What is the dictionary form of luotan, and why does tt become t?

The dictionary form is luottaa. In many Finnish verbs, consonant gradation changes the “strong” grade in the dictionary form to a “weak” grade in some conjugated forms.
Here: luottaa → luotan ( tt → t )
This is a common pattern (strong grade in the infinitive, weaker grade in some present forms).

Why is it tähän and not tätä?

Because luottaa typically requires its complement in the illative case (meaning roughly into / onto / in(to) in form, but idiomatically trust in).
So you say: luottaa johonkin = to trust in something.

• tämä (this) in the illative singular is tähän
  Whereas tätä is the partitive form (used with many other verbs/contexts), but not the normal case after luottaa.

Why does kurssi become kurssiin?

Because kurssiin is the illative singular of kurssi. The illative often answers into what? / to what? (and with luottaa, it’s the required case).
For many -i ending nouns like kurssi, the illative singular is formed with -in, and you typically get a long vowel:

• kurssi → kurssiin (roughly: add -in, and i lengthens to ii)

Why are both words in the same case: tähän kurssiin?

Because tähän is a demonstrative (like this) modifying the noun kurssi, and Finnish requires case agreement inside the noun phrase: the modifier takes the same case and number as the noun.
So:

• nominative: tämä kurssi
• illative: tähän kurssiin
• inessive: tässä kurssissa, etc.

Is kurssiin the “object” of the sentence?

Not in the typical “direct object” sense (like something you do/affect). With luottaa, the noun phrase is best thought of as a case-governed complement (often called verb rection): the verb requires illative.
So it functions more like trust in X than like a direct object.

Can I change the word order, or is it fixed?

You can change it for emphasis or contrast, because Finnish word order is fairly flexible:

• Luotan tähän kurssiin. (neutral)
• Tähän kurssiin luotan. (emphasizes this course specifically)
• Luotan kurssiin. (more general: I trust the course)
  The case endings keep the roles clear even if the order changes.

Do I need to include minä (I), or is it optional?

It’s optional. The verb form luotan already shows the subject is I.

• Luotan tähän kurssiin. (very common)
• Minä luotan tähän kurssiin. (adds emphasis: I do / as for me)

How would this change if I said I trust you or I trust my friend?

You still use luottaa + illative:

• I trust you (singular): Luotan sinuun. (sinä → sinuun, illative)
• I trust him/her: Luotan häneen.
• I trust my friend: Luotan ystävääni. (often illative-looking form; the key idea is still trust in someone)
  In general: Luotan + (person/thing) in illative.

How is this sentence pronounced, and where is the stress?

Primary stress in Finnish is almost always on the first syllable of each word:

• LUO-tan TÄ-hän KURS-siin
  Also note vowel length matters: kurssiin has a long ii sound, which is important for meaning and correctness.