<p>I Since / For</p>
<p>1.) <strong>for</strong> a very long time.</p>
<p>2.) <strong>since</strong> I left school.</p>
<p>3.) <strong>for</strong> 10 years.</p>
<p>4.) <strong>since</strong> it started to rain.</p>
<p>5.) <strong>for</strong> three weeks.</p>
<p>6.) <strong>since</strong> September.</p>
<p>7.) <strong>since</strong> I came to London.</p>
<p>8.) <strong>for</strong> half an hour.</p>
<p>9.) <strong>since</strong> my birthday.</p>
<p>10.) <strong>for</strong> six months.</p>
<p>II Since / For</p>
<p>1.) I have been a teacher <strong>for</strong> 30 years.</p>
<p>2.)<span> Bob has worked in that import export company <strong>since</strong> he was thirty.</span></p>
<p><span>3.) <span>I have studied English <strong>for</strong> four years.</span></span></p>
<p><span><span>4.) <span>Jenny has eaten  five hamburgers <strong>since</strong> 7pm.</span></span></span></p>
<p><span><span><span>5.) <span>My parents have been married <strong>for</strong> twenty years.</span></span></span></span></p>
<p><span><span><span><span>6.) <span>I have known my best friend <strong>since</strong> <span>I met him at high school.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>7.) <span>They have travelled in the USA <strong>for</strong> one month.</span></span></span></span></span></span></span></p>
<p><span><span><span><span><span><span><span>8.) <span>The boys have played tennis <strong>for</strong> two hours.</span></span></span></span></span></span></span></span></p>
<p><span><span><span><span><span><span><span><span>9.) <span>Kevin has been in Greece <strong>since</strong> July.</span></span></span></span></span></span></span></span></span></p>
<p><span><span><span><span><span><span><span><span><span>10.) <span>My  brother has  drunk beer <strong>for</strong> two hours.</span></span></span></span></span></span></span></span></span></span></p>
<p><span><span><span><span><span><span><span><span><span><span>11.) <span>I haven't eaten anything <strong>since</strong> lunch.</span></span></span></span></span></span></span></span></span></span></span></p>