Learn Hardcore Finnish: Minä opiskelen suomea mieluummin aamulla, mutta toisinaan illalla. - I prefer to study Finnish in the morning, but sometimes in the evening.

Yes. Finnish personal pronouns are often omitted because the verb ending (-n) shows the subject (“I”). Including minä adds emphasis or clarity, especially for learners or in contrastive contexts.

Why is suomea in the partitive case instead of the nominative suomi?

After verbs like opiskella, the object is in the partitive case to indicate an ongoing or incomplete action. Learning a language is an unbounded process, so you say suomea (partitive), not suomi (nominative).

What does mieluummin mean, and how is it different from mielellään?

mieluummin means “rather” or “prefer,” expressing a comparison between options.
mielellään means “gladly” or “with pleasure,” indicating you like doing something without comparing alternatives.

Why do we use the adessive case for aamulla instead of just aamu or the essive aamuna?

Time-of-day expressions in Finnish use the adessive case (-lla/-llä) to mean “in the _.”
• aamulla = “in the morning”
• illalla = “in the evening”
Using aamu alone would be ungrammatical in this context, and aamuna (essive) would mean something like “as a morning,” which doesn’t work here.

Could I say opiskelen mieluummin suomea aamulla? Would that change the meaning?

Yes, that word order is grammatically correct. Finnish word order is flexible:
• Placing mieluummin immediately after the verb highlights your preference as a modifier of the action.
• The original sequence (verb + object + manner + time) is most neutral and common.
All variants are understood, but slight shifts in emphasis may occur.

Why is mutta used here instead of ja or sekä?

mutta means “but” and signals a contrast between your preferred study time (morning) and the occasional evening sessions.
• ja or sekä would mean “and,” simply linking two facts without that contrast.

What’s the difference between toisinaan and joskus? Could I say joskus illalla instead?

• toisinaan = “occasionally,” implying somewhat regular but infrequent occurrences.
• joskus = “sometimes,” more general and colloquial.
You can use joskus illalla, but toisinaan sounds slightly more formal or literary.

Why do we need both toisinaan and illalla? Aren’t they both time expressions?

They play different roles:

toisinaan indicates frequency (“occasionally”).
illalla specifies the time of day (“in the evening”).
Together they mean “occasionally, and when you do, it’s in the evening.”

Why is illalla also in the adessive case (-lla)?

For the same reason as aamulla: Finnish uses the adessive case for “in the _” time expressions.

Why is the verb opiskelen in the present tense? Can it express a habitual action?

Yes. In Finnish the simple present tense covers both actions happening right now and habitual or regular actions. Context (your stated preference/routine) shows it’s a habitual activity.