Tense in German

I learned deutsch yesterday from a private tutor. I found out that I had been using some tenses incorrectly. I often use the perfect tense instead of the past tense for an event occurred in the past. 

The past tense is used for  an event which had already finished in the past. The perfect tense can be used to talk about the event in the past, but that event still has some effect until present. 

For example, If I want to say that I slept yesterday, and then event was already finished yesterday. Then, I should say, “Gestern schlief Ich.” However, if I just slept, and I still have some effect from that sleep like feeling sleepy. Then, I could say, “Ich habe geschalafen” to describe that I slept in the past.

 

I also though that I could use the  present tense to describe an event in the future and use adverb (e.g. tomorrow (Morgen)) to indicate that it will be happen in the future. I also found out that present tense is used instead of the future tense when the event is always happen. If the event in the future is planned to happen (it is not usually happened), then the future tense should be used.

For example, if tomorrow is Saturday. If I usually wash my cloth on Saturday. Then, I could say, “Am Morgen wasche ich meine Kleider (Tomorrow, I wash my cloth). If I don’t usually wash cloth on Saturday, but I plan to wash cloth tomorrow which is Saturday. Then, I could say, “Am morgen werde ich meine Kleider waschen.”