Translation guide
In Japanese, 'one suit' is typically expressed using the counter 着 (ちゃく) for suits, combined with the number one (一). The phrase 一着 (いっちゃく) means 'one suit' in the sense of a single set of clothing. This entry covers how to count suits and related expressions.
The learner wants to say 'one suit' as in a single set of matching jacket and trousers/skirt.
This is the standard way to say 'one suit' using the counter 着 for suits and other sets of clothing. It is neutral and can be used in most contexts.
I bought one new suit.
This one suit was very expensive.
Adding スーツ before the counter makes it explicit that you are talking about a suit. This is common when the context isn't already clear.
I took one suit to the dry cleaners.
The learner wants to emphasize 'one suit' in contrast to multiple suits, or when selecting from a group.
Using の to connect the counter to the noun is a common pattern for 'one [noun]'. It can sound slightly more descriptive or emphatic.
One suit is enough.
The learner wants to refer to one of the four suits in a deck of cards (hearts, diamonds, clubs, spades).
In card games, 'suit' is usually スート (from English). To say 'one suit', use 一つのスート. This is the most natural way.
It's a game where you collect only one suit.
マーク is sometimes used for card suits, though スート is more specific. This is acceptable but less common.
The heart symbol is one suit.
While 一つ (ひとつ) is the generic counter for 'one thing', it is not used for suits. Always use the specific counter 着 (ちゃく) for suits and other sets of clothing like jackets, coats, and dresses.
The counter 着 is used for items of clothing that are worn on the upper body or as a full set. For pants or skirts alone, use 本 (ほん) or other counters. A suit is considered one 着 because it's a coordinated set.