Learn Hardcore German: Diese Phase macht mich manchmal nervös, aber ich bleibe optimistisch. - This phase sometimes makes me nervous, but I remain optimistic.

Das macht mich traurig. – That makes me sad.
Die Situation macht ihn wütend. – The situation makes him angry.
Lange Wartezeiten machen viele Leute ungeduldig. – Long waiting times make many people impatient.

So Diese Phase macht mich nervös is a very natural, idiomatic way to say that this phase causes you to feel nervous.

Why is it mich and not mir in Diese Phase macht mich nervös?

Mich is accusative; mir is dative.

In this sentence, mich is the direct object of macht (what does this phase make? – it makes me nervous). Direct objects use the accusative case, so you need mich.

Compare:

Diese Phase macht mich nervös.
– This phase makes me nervous.
(mich = direct object → accusative)
Diese Phase macht mir Angst.
– This phase frightens me / gives me fear.
(mir goes with Angst machen, which is treated more like give someone fear → indirect object → dative)

So the choice between mich and mir depends on the verb and the construction, not on the English translation alone.

Why is it diese Phase and not dieser Phase?

Because Phase is the subject of the sentence and is feminine.

The base noun is die Phase (feminine).
Here it is the subject → nominative case.
The correct demonstrative determiner for feminine nominative singular is diese.

Rough mini-paradigm for the singular of dies-:

Masculine: dieser (Nom.), diesen (Acc.)
Feminine: diese (Nom. & Acc.)
Neuter: dieses (Nom. & Acc.)

So:

Diese Phase macht mich nervös. – nominative feminine → diese
Ich widme mich dieser Phase. – dative feminine → dieser

What case is Phase in, and how can I tell?

Phase is in the nominative case because it is the subject of the verb macht.

Structure:

Diese Phase – subject (what is doing the making?)
macht – verb
mich – direct object (accusative)
nervös – predicate adjective

In a neutral word order German main clause, the subject is usually just before the conjugated verb, which is another clue that Diese Phase is the nominative subject here.

Why is manchmal placed after mich? Could it go somewhere else?

Manchmal (sometimes) is a time adverb, and German gives you some flexibility in where to put it.

In Diese Phase macht mich manchmal nervös:

Diese Phase = subject
macht = verb
mich = pronoun object
manchmal = time adverb
nervös = adjective

This is a natural word order: pronoun object (mich) is kept close to the verb, and the adverb (manchmal) comes right after it.

Other common, correct options:

Manchmal macht mich diese Phase nervös.
– Puts more emphasis on sometimes.
Diese Phase macht mich nervös, manchmal.
– Stylistic, adds a slight pause/afterthought feel.

Much less natural or wrong would be:

Diese Phase macht manchmal mich nervös. – sounds awkward; pronouns usually come earlier than adverbs.

So yes, manchmal can move, but the original placement is very typical.

Why is there a comma before aber?

In German, you must use a comma before coordinating conjunctions like aber when they join two full clauses (each with its own subject and verb).

Here you have:

Diese Phase macht mich manchmal nervös
– subject: Diese Phase, verb: macht
ich bleibe optimistisch
– subject: ich, verb: bleibe

Because both parts are full clauses, you write:

Diese Phase macht mich manchmal nervös, aber ich bleibe optimistisch.

So the comma is mandatory by standard German punctuation rules.

Why aber and not sondern or doch or trotzdem?

Each of these has a different use:

aber = but / however
Neutral contrast. That’s what we want here: I’m nervous, but I stay optimistic.
sondern = but rather / but instead
Used after a negation to correct something:
- Ich bin nicht nervös, sondern entspannt.
  – I’m not nervous, but (instead) relaxed.
doch (as a conjunction) = but / however / yet
Often adds a bit more emotional or surprising contrast, similar to English yet:
- Diese Phase macht mich manchmal nervös, doch ich bleibe optimistisch.
  – stylistically fine, somewhat more formal/literary.
trotzdem = nevertheless / in spite of that
It is usually an adverb starting a new clause, not a simple conjunction:
- Diese Phase macht mich manchmal nervös. Trotzdem bleibe ich optimistisch.

In your sentence, aber is the most straightforward and neutral choice.

Why is it ich bleibe optimistisch and not ich bin optimistisch?

bleiben = to remain / to stay
sein = to be

Ich bleibe optimistisch emphasizes continuity:
You are saying: I stay / remain optimistic (despite this).

Ich bin optimistisch would just state a present fact: I am optimistic, without the nuance of continuing to be in spite of something.

So using bleibe matches the contrast:

This phase makes me nervous, but I remain optimistic.

Why don’t nervös and optimistisch have endings like nervöse or optimistische here?

Because in this sentence they are predicate adjectives, not adjectives directly attached to a noun.

Two main uses of adjectives in German:

Attributive (before a noun) – they take endings:
- eine nervöse Phase – a nervous phase
- ein optimistischer Mensch – an optimistic person
Predicative (after verbs like sein, werden, bleiben, machen) – no endings:
- Diese Phase macht mich nervös.
- Ich bleibe optimistisch.
- Er ist müde.
- Sie wird krank.

In your sentence, nervös describes mich, and optimistisch describes ich, but both appear after the verb, so they stay in the base form, without endings.

Could I just say Diese Phase macht mich nervös and drop manchmal?

Yes. Grammatically that is perfectly fine:

Diese Phase macht mich nervös, aber ich bleibe optimistisch.

The only difference is in meaning/nuance:

With manchmal: it happens sometimes, not all the time.
Without manchmal: it suggests the phase generally or regularly makes you nervous.

So manchmal limits the frequency of the feeling.

What is the difference between nervös and nervig? Could I say Diese Phase ist nervig instead?

Yes, you can say Diese Phase ist nervig, but it means something slightly different:

nervös = nervous, describing a person’s emotional state
- Ich bin nervös. – I’m nervous.
nervig = annoying / irritating, describing that something gets on your nerves
- Diese Phase ist nervig. – This phase is annoying.

In your original sentence:

Diese Phase macht mich nervös
means: this phase causes you to feel nervous.

If you say:

Diese Phase ist nervig
you’re judging the phase itself as annoying, not describing your inner nervousness (though often the two are related).

Is Phase always feminine, and how am I supposed to know its gender?

Yes, Phase is always feminine: die Phase.

For German nouns, gender is mostly lexical (you have to learn it with the word), but there are some tendencies:

Many nouns ending in -e are feminine:
die Schule, die Straße, die Lampe, die Reise, die Phase
(But not all: der Name, der Junge are exceptions.)
Dictionaries and vocab lists always show nouns with their article:
die Phase, der Tisch, das Problem.

Best habit: when you learn a new noun, learn it together with its article:

Not just Phase, but die Phase.