This depends on what language you speak and what you want to learn.
(Check our Language Difficulty Guide).
If you want to learn an unrelated language as your first foreign language, you'll probably find Glossika frustrating because we don't explain anything. If it's a similar language, you should be able to recognize familiar parts of speech.
The pronouns, verbs, and nouns are easy to look up online and get a feel for how they work, then you can come back to Glossika and give it a try.
Glossika's magic happens when you recognize bits and pieces and understand half of a sentence. Your mind finds a way to figure out the other half.