Run-on sentences and comma splices

These sentences are the opposite of sentence fragments. They combine two main clauses that could be expressed as independent sentences but without a coordinating conjunction such as and, but, or or for. I have decided to include comma splices, i.e. sentences in which a comma creates ambiguity or generally makes the structure unclear. Look at the following examples and their corrections.

a. *I like bananas they are very healthy. *I like bananas, they are very healthy. => I like bananas. They are very healthy. I like bananas because/for they are very healthy. I like bananas; they are very healthy.

b. *Henry said he didn't like gardening, however, he spent all day weeding and mowing his lawn. =>
Henry said he didn't like gardening. However, he spent...   Henry said he didn't like gardening; however, he spent...   Although Henry said he didn't like gardening, he spent...

Since however can be attached at the end of a clause, if the starred sentence in b. is preceded by other sentences, it is not clear whether the contrast refers to the first clause or the second one. That is why a full stop or a semi-colon is necessary.

Ex. Correct the following sentences.

1. English is not the only language worth studying, actually, Spanish is important too.
2. I had a terrible day my car broke down and my dog peed on the carpet.
3. She's always talking about her health problems it's quite annoying.
4. Julia's alarm clock didn't work, however, she woke up at six.
5. Have you bought the dictionary our teacher recommended I've bought a used copy online.
6. Jake is a good friend of mine, we went to school together.
7. Kate likes tea, her boyfriend prefers coffee. 
8. Most foreigners think that the books about the Moomins were written in Finnish, however, few realise they were written in Swedish.
9. I once attended a Business English course now I can't remember anything.
10. In American movies all French people smoke besides you can see the Eiffel Tower from any spot in Paris.

KEY (sometimes more options are possible)

1. ... studying. Actually, Spanish... / studying. Actually, Spanish... 2. ... day: my car... / ... day, because my car ... 3. ... her health problems. It's quite annoying. / ... her health problems; it's quite... / ... her health problems, which is... 4. ... work. However, she / ... work; however, she... / Although Julia's alarm clock didn't work, she (nonetheless) woke up at six. 5. ... recommended? I've bought... 6. ... of mine. We went to school... / ... of mine; we went to school ... 7. Kate likes tea while/whereas/and her boyfriend prefers coffee. 8. ... in Finnish. However, few ... / ... in Finnish; however, few ... 9. ... a Business English course, but now ... / ... course. Now ... 10. .. smoke. Besides, you ... / smoke, and you ...