Learn Finnish: Hän lukee palautteen myöhemmin ja ajattelee uutta menetelmää. - He reads the feedback later and thinks about a new method.

Myöhemmin means "later." It is the comparative form of the adverb myöhään (late). To form a comparative adverb, you generally take the strong stem of the word and add the suffix -mmin. Here, the stem is myöhe-, which gives us myöhemmin.

Why does "palautteen" end in '-n' (accusative) while "uutta menetelmää" is in the partitive case?

This happens because of the different verbs. The verb lukea (to read) takes an accusative object here (ending in -n) because reading the feedback is a completed action—he reads the whole thing. However, the verb ajatella (to think about) is a "partitive verb," meaning the object that follows it must always be in the partitive case (uutta menetelmää).

The base word for "feedback" is "palaute". Why does it have a double '-tt-' in "palautteen"?

Nouns ending in -e follow a "reverse" consonant gradation rule. Their basic dictionary form uses the weak consonant grade (a single -t- in palaute), but their word stem uses the strong grade. When we form the stem to add the -n ending, the single -t- strengthens into a double -tt-, becoming palautteen.

How do we get the form "ajattelee" from the basic verb "ajatella" (to think)?