verb form mistakes

When I speak English, I often make mistakes like,

"He speak English" instead of "He speaks English"
"I go there yesterday" instead of "I went there yesterday"

I know the grammatical rule, but I have to speak quickly in the conversation so my brain cannot catch up.
Does anyone have any suggestions to practice speaking skills to and overcome this situation?

verb form mistakes

When I speak English, I often make mistakes like,

"He speak English" instead of "He speaks English"
"I go there yesterday" instead of "I went there yesterday"

I know the grammatical rule, but I have to speak quickly in the conversations so my brain cannot catch up.
Does anyone have any suggestions to practice(practise is the only verb for non-USA countries) speaking skills which can overcome this situation?

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It seems that forgetfulness of tense-changing when using English is one of the most common grammatical errors of non-native English users. Keeping over-attention to verbs helps but sometimes you may start making other common mistakes like no-s-after-plural or wrong agreements.

What I tried is that, I pay attention on words that are often changing from time to time, like countable nouns, and verbs. They are often the key parts of the sentences too, so they are worth thinking and worth waiting. Making sentences orally is like playing a music: If you do it more slowly, you are more likely to make a correctly one; and when you get more familiar, you can play it faster. Starting with a fast speed is a bad habit, no matter to the grammatical correctness, or to the pronunciation.