I am capable of swimming in the sea.
I am able to swim in the sea.
I can swim in the sea.
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Are they all the same and grammatical?
Yes. The are all the same and grammatical.
Yes, all three sentences are grammatically correct and convey the same meaning. They express the ability to swim in the sea. However, there are slight differences in terms of usage and emphasis:
1. "I am capable of swimming in the sea" - This sentence emphasizes the capability or proficiency of the speaker in swimming in the sea.
2. "I am able to swim in the sea" - This sentence emphasizes the ability or possibility of the speaker to swim in the sea.
3. "I can swim in the sea" - This sentence is a simple statement of ability without any particular emphasis.
In everyday conversation, all three sentences can be used interchangeably, and the choice depends on personal preference or the desired emphasis.