Sure, let's go through each sentence and put the verbs in the correct form. I'll also explain the reasoning behind each choice.

1. If I see him, I **will give** him a gift.
- This is a first conditional sentence, which is used for real and possible situations in the future. The structure is: If + present simple, will + base verb.

2. If I had a typewriter, I **would type** it myself.
- This is a second conditional sentence, which is used for unreal or hypothetical situations in the present or future. The structure is: If + past simple, would + base verb.

3. If I **knew** his telephone number, I'd give it to you.
- This is also a second conditional sentence. The past simple form of "know" is "knew".

4. You could make better progress if you **attended** class regularly.
- This is a second conditional sentence. The past simple form of "attend" is "attended".

5. If I had known that you were in hospital, I **would have visited** you.
- This is a third conditional sentence, which is used for unreal situations in the past. The structure is: If + past perfect, would have + past participle.

6. If you **had arrived** ten minutes earlier, you would have got a seat.
- This is a third conditional sentence. The past perfect form of "arrive" is "had arrived".

7. A lot of people **would be** out of work if the factory closed down.
- This is a second conditional sentence. The structure is: If + past simple, would + base verb.

8. I wouldn't drink that wine if I **were** you.
- This is a second conditional sentence. In formal English, "were" is used instead of "was" after "if" in hypothetical situations.

9. If I **find** a cheap room, I will stay a fortnight.
- This is a first conditional sentence. The structure is: If + present simple, will + base verb.

10. If he worked more slowly, he **would not make** so many mistakes.
- This is a second conditional sentence. The structure is: If + past simple, would + base verb.

I hope this helps! Let me know if you have any more questions.