Duolingo is pretty good for the beginning, but it teaches a lot of nonsense (it wanted me to say 'I'm a turtle' in French). I came across a website/app called
Mondly, which I think is much better because it teaches useful sentences grouped in different themes. I use it to learn Danish, and it's really helpful. Mondly has a bot that you can actually talk to. It records your voice, analyses your pronounciation and gives you feedback on that. If you don't want to talk, you can also chat with it to practice phrases you'd use in conversations.
Mondly is pretty good for learning grammar, too. You have full sentences with a structure, and you can tap on any verb to see all the tenses. That was something I missed in Duolingo, and I found it in Mondly.
There is a premium version of it, but as far as I know, the only difference between the free one and the premium one is that with premium you can do the daily lessons at any time and not only the day they come out. If you're not as lazs as me, you can do one of those daily lessons every day so you don't need premium to go back and do them later
Another website I use for learning languages is
Memrise. It's not very good for grammar or complete sentences, but if you're looking for a way to grow your vocabulary, it's probably the best way to do it. I use it to improve my English (my native language is German) and to learn new words in Danish which I can then use in the sentences I learned in Mondly.
I hope this was helpful for you
