Translation guide
The English phrase 'at first' describes an initial state or action that later changes. In Japanese, this is commonly expressed with adverbs like 最初は or 初めは, or with the grammar pattern ～た時は～が、今は～. The choice depends on whether you are contrasting past and present, describing a first impression, or narrating a sequence of events.
At first it was hard, but I got used to it.
To describe how something was in the beginning, implying that it is different now.
The most common and neutral way to say 'at first'. It sets up a contrast with the current situation.
At first it was difficult, but now it's easy.
At first I didn't like him.
Very similar to 最初は, but can feel slightly more subjective or personal. Often interchangeable.
At first I thought so.
A sentence pattern that explicitly contrasts the past and present. Use the past tense verb before 時.
When I first came to Japan I couldn't speak Japanese, but now I can.
Formal, often used in written or business contexts. Implies 'initially' or 'at the outset'.
At first, things were going according to plan.
To express a first impression or immediate reaction, often followed by a change of opinion.
To indicate the starting point of a sequence of events, without necessarily implying a contrast.
The phrase 'at first' implies a change over time. If you mean 'for the first time' (as in a new experience), use 初めて (はじめて).
I ate sushi for the first time.
Adding は after time expressions like 最初 or 初め emphasizes the contrast with the present. Without は, it may simply mean 'first' in a sequence.
At first when we met, we didn't talk much.