つつある (tsutsu-aru): Be gradually becoming; be in the process of
～つつある (tsutsu-aru)
Meaning
Be gradually becoming; be in the process of
Formation and usage
V stem + つつある
Notation: N = noun; V dictionary = dictionary-form verb; V stem = the stem before ます; plain clause = plain-form clause; negative stem = the form before ない. Follow the attachment shown above.
Explanation
Highlights an ongoing change, rather than serving as a general replacement for every progressive form.
Examples
日本語への関心が高まりつつある。
Interest in Japanese is gradually growing.
英語への関心が高まりつつある。
Interest in English is gradually growing.
料理への関心が高まりつつある。
Interest in cooking is gradually growing.
運転への関心が高まりつつある。
Interest in driving is gradually growing.
接客への関心が高まりつつある。
Interest in customer service is gradually growing.
How related patterns differ
いつのまにか highlights a change whose timing went unnoticed. つつある describes an ongoing change, and うちに describes a change during a period. つい concerns an unintentional action, while たとたんに emphasizes a particular instant.